Without time, there would be no need for a memory. But without a memory, would there be such a thing as time? I don't mean time in the sense that, say, physicists speak of it: the fourth dimension, the independent variable, the quant.i.ty that compresses when you approach the speed of light. I mean psychological time, the tempo at which we experience life's pa.s.sage. Time as a mental construct. Watching EP struggle to recount his own age, I recalled one of the stories Ed Cooke had told me about his research at the University of Paris when we met at the U.S. Memory Championship.

"I'm working on expanding subjective time so that it feels like I live longer," Ed had mumbled to me on the sidewalk outside the Con Ed headquarters, a cigarette dangling from his mouth. "The idea is to avoid that feeling you have when you get to the end of the year and feel like, where the h.e.l.l did that go?"

"And how are you going to do that?" I asked.

"By remembering more. By providing my life with more chronological landmarks. By making myself more aware of time's pa.s.sage."

I told him that his plan reminded me of Dunbar, the pilot in Joseph h.e.l.ler's Catch-22 Catch-22 who reasons that since time flies when you're having fun, the surest way to slow life's pa.s.sage is to make it as boring as possible. who reasons that since time flies when you're having fun, the surest way to slow life's pa.s.sage is to make it as boring as possible.

Ed shrugged. "Quite the opposite. The more we pack our lives with memories, the slower time seems to fly."

Our subjective experience of time is highly variable. We all know that days can pa.s.s like weeks and months can feel like years, and that the opposite can be just as true: A month or year can zoom by in what feels like no time at all.

Our lives are structured by our memories of events. Event X happened just before the big Paris vacation. I was doing Y in the first summer after I learned to drive. Z happened the weekend after I landed my first job. We remember events by positioning them in time relative to other events. Just as we acc.u.mulate memories of facts by integrating them into a network, we acc.u.mulate life experiences by integrating them into a web of other chronological memories. The denser the web, the denser the experience of time.

It's a point well ill.u.s.trated by Michel Siffre, a French chron.o.biologist (he studies the relationship between time and living organisms) who conducted one of the most extraordinary acts of self-experimentation in the history of science. In 1962, Siffre spent two months living in total isolation in a subterranean cave, without access to clock, calendar, or sun. Sleeping and eating only when his body told him to, he sought to discover how the natural rhythms of human life would be affected by living "beyond time."

Very quickly Siffre's memory deteriorated. In the dreary darkness, his days melded into one another and became one continuous, indistinguishable blob. Since there was n.o.body to talk to, and not much to do, there was nothing novel to impress itself upon his memory. There were no chronological landmarks by which he could measure the pa.s.sage of time. At some point he stopped being able to remember what happened even the day before. His experience in isolation had turned him into EP. As time began to blur, he became effectively amnesic. Soon, his sleep patterns disintegrated. Some days he'd stay awake for thirty-six straight hours, other days for eight-without being able to tell the difference. When his support team on the surface finally called down to him on September 14, the day his experiment was scheduled to wrap up, it was only August 20 in his journal. He thought only a month had gone by. His experience of time's pa.s.sage had compressed by a factor of two.

Monotony collapses time; novelty unfolds it. You can exercise daily and eat healthily and live a long life, while experiencing a short one. If you spend your life sitting in a cubicle and pa.s.sing papers, one day is bound to blend unmemorably into the next-and disappear. That's why it's important to change routines regularly, and take vacations to exotic locales, and have as many new experiences as possible that can serve to anchor our memories. Creating new memories stretches out psychological time, and lengthens our perception of our lives.

William James first wrote about the curious warping and foreshortening of psychological time in his Principles of Psychology Principles of Psychology in 1890: "In youth we may have an absolutely new experience, subjective or objective, every hour of the day. Apprehension is vivid, retentiveness strong, and our recollections of that time, like those of a time spent in rapid and interesting travel, are of something intricate, mult.i.tudinous and long-drawn-out," he wrote. "But as each pa.s.sing year converts some of this experience into automatic routine which we hardly note at all, the days and the weeks smooth themselves out in recollection to contentless units, and the years grow hollow and collapse." Life seems to speed up as we get older because life gets less memorable as we get older. "If to remember is to be human, then remembering more means being more human," said Ed. in 1890: "In youth we may have an absolutely new experience, subjective or objective, every hour of the day. Apprehension is vivid, retentiveness strong, and our recollections of that time, like those of a time spent in rapid and interesting travel, are of something intricate, mult.i.tudinous and long-drawn-out," he wrote. "But as each pa.s.sing year converts some of this experience into automatic routine which we hardly note at all, the days and the weeks smooth themselves out in recollection to contentless units, and the years grow hollow and collapse." Life seems to speed up as we get older because life gets less memorable as we get older. "If to remember is to be human, then remembering more means being more human," said Ed.

There is perhaps a bit of Peter Pan to Ed's quest to make his life maximally memorable, but of all the things one could be obsessive about collecting, memories of one's own life don't seem like the most unreasonable. There's something even strangely rational about it. There's an old philosophical conundrum that often gets bandied about in introductory philosophy courses: In the nineteenth century, doctors began to wonder whether the general anesthetic they had been administering to patients might not actually put the patients to sleep so much as freeze their muscles and erase their memories of the surgery. If that were the case, could the doctors be said to have done anything wrong? Like the proverbial tree that falls without anyone hearing it, can an experience that isn't remembered be meaningfully said to have happened at all? Socrates thought the unexamined life was not worth living. How much more so the unremembered life?

Much of what science knows about memory was learned from a damaged brain remarkably similar to EP's. It belonged to another amnesic named Henry Molaison, who went by the initials HM and spent most of his life in a nursing home in Connecticut before dying in 2008. (Individuals in the medical literature always go by initials to protect their ident.i.ties. HM's name was revealed after his death.) As a child, HM suffered from epilepsy, which began after a bike accident at age nine. By the time he was twenty-seven, he was blacking out several times a week and unable to do much of anything. A neurosurgeon named William Scoville thought he could relieve HM's symptoms with an experimental surgery that would excise the part of the brain that he suspected was causing the problem. science knows about memory was learned from a damaged brain remarkably similar to EP's. It belonged to another amnesic named Henry Molaison, who went by the initials HM and spent most of his life in a nursing home in Connecticut before dying in 2008. (Individuals in the medical literature always go by initials to protect their ident.i.ties. HM's name was revealed after his death.) As a child, HM suffered from epilepsy, which began after a bike accident at age nine. By the time he was twenty-seven, he was blacking out several times a week and unable to do much of anything. A neurosurgeon named William Scoville thought he could relieve HM's symptoms with an experimental surgery that would excise the part of the brain that he suspected was causing the problem.

In 1953, while HM lay awake on the operating table, his scalp anesthetized, Scoville drilled a pair of holes just above the patient's eyes. The surgeon lifted the front of HM's brain with a small metal spatula while a metal straw sucked out most of the hippocampus, along with much of the surrounding medial temporal lobes. The surgery reduced the number of HM's seizures, but there was a tragic side effect: It soon became clear that he'd also been robbed of his memory.

Over the next five decades, HM was the subject of countless experiments and became the most studied patient in the history of brain science. Given the horrific outcome of Scoville's surgery, everyone a.s.sumed HM would be a singular case study.

EP shattered that a.s.sumption. What Scoville did to HM with a metal straw, nature did to EP with herpes simplex. Side by side, the grainy black-and-white MRIs of their brains are uncannily similar, though EP's damage is a bit more extensive. Even if you have no idea what a normal brain ought to look like, the two gaping symmetrical holes stare back at you like a pair of shadowy eyes.

Like EP, HM was able to hold on to memories just long enough to think about them, but once his brain moved on to something else, he could never bring them back. In one famous experiment conducted by the Canadian neuroscientist Brenda Milner, HM was asked to remember the number 584 for as long as possible. He spoke aloud as he was doing it: It's easy. You just remember 8. You see, 5, 8, and 4 add to 17. You remember 8, subtract it from 17 and it leaves 9. Divide 9 in half and you get 5 and 4 and there you are: 584. Easy.

He concentrated on this elaborate mantra for several minutes. But as soon as he was distracted, the number dissolved. He couldn't even remember that he'd been asked to remember something. Though scientists had known that there was a difference between long- and short-term memory since the late nineteenth century, they now had evidence in HM that the two types of memory processes happened in different parts of the brain, and that without most of the hippocampal area, HM couldn't turn a short-term memory into a long-term one.

Researchers also learned more about another kind of remembering from HM. Even though he couldn't say what he'd had for breakfast or name the current president, there were some things that he could recall. Milner found that he could learn complicated tasks without even realizing it. In one landmark study in 1962, she showed that HM could learn how to trace inside a five-pointed star on a piece of paper while looking at its reflection in a mirror. Each time Milner gave HM the task, he claimed never to have tried it before. And yet, each day his brain got better at guiding his hand to work in reverse. Despite his amnesia, he was remembering.

Subsequent studies of amnesics, including tests conducted on EP, have found that people who lose their memories are still capable of yet other kinds of unremembered learning. In one experiment, Squire gave EP a list of twenty-four words to memorize. As expected, within a few minutes, EP had no recollection of any of the words, or even that the exercise had happened at all. When asked whether he'd seen a given word before, he answered correctly only half the time. But then Squire sat EP in front of a computer monitor and gave him a different test. This time, forty-eight words were flashed on the screen for twenty-five milliseconds each, just long enough for the eye to catch some, but not all, of them (an eye blink, by comparison, happens in 100 to 150 milliseconds). Half the words were from the list that EP had read over and forgotten, and half were new. Squire asked EP to read each word after it flashed on the screen. Surprisingly, EP was far better at reading the words he'd seen before than the ones that were new. Even though he had no conscious recollection of them, somewhere in the recesses of his brain they had left an impression.

This phenomenon of unconscious remembering, known as priming, is evidence of an entire shadowy underworld of memories lurking beneath the surface of our conscious reckoning. Though there is disagreement about just how many memory systems there are, scientists generally divide memories broadly into two types: declarative and nondeclarative (sometimes referred to as explicit and implicit). Declarative memories are things you know you remember, like the color of your car, or what happened yesterday afternoon. EP and HM had lost the ability to make new declarative memories. Nondeclarative memories are the things you know unconsciously, like how to ride a bike or how to draw a shape while looking at it in a mirror (or what a word flashed rapidly across a computer screen means). Those unconscious memories don't seem to pa.s.s through the same short-term memory buffer as declarative memories, nor do they depend on the hippocampal region to be consolidated and stored. They rely primarily on different parts of the brain. Motor skill learning takes place largely in the cerebellum, perceptual learning in the neocortex, habit learning in the basal ganglia. As EP and HM have so strikingly demonstrated, you can damage one part of the brain, and the rest will keep on working. Indeed, most of who we are and how we think-the core material of our personalities-is bound up in implicit memories that are off-limits to the conscious brain.

Within the category of declarative memories, psychologists make a further distinction between semantic memories, or memories for facts and concepts, and episodic memories, or memories of the experiences of our own lives. Recalling that I had eggs for breakfast this morning would be an episodic memory. Knowing that breakfast is the first meal of the day is a semantic memory. Episodic memories are located in time and s.p.a.ce: They have a where and a when attached to them. Semantic memories are located outside of time and s.p.a.ce, as free-floating pieces of knowledge. These two different types of remembering seem to make use of different neural pathways, and rely on different regions of the brain, though both are critically dependent on the hippocampus and other structures within the medial temporal lobes. EP has lost both types of memory in equal measure, but curiously his forgetfulness extends back only for the last sixty or so years. His memories have faded along a gradient.

One of the many mysteries of memory is why an amnesic like EP should be able to remember when the atomic bomb fell on Hiroshima but not the much more recent fall of the Berlin Wall. For some unknown reason, it's the most recent memories that blur first in most amnesics, while distant memories retain their clarity. This phenomenon is known as Ribot's Law, after the nineteenth-century French psychologist who first noted it, and it's a pattern found also in Alzheimer's patients. It suggests something profound: that our memories are not static. Somehow, as memories age, their complexion changes. Each time we think about a memory, we integrate it more deeply into our web of other memories, and therefore make it more stable and less likely to be dislodged.

But in the process, we also transform the memory, and reshape it-sometimes to the point that our memories of events bear only a pa.s.sing resemblance to what actually happened. Neuroscientists have only recently begun to observe this process happening inside the brain, but psychologists have understood for a long time that there are qualitative differences between old and new memories. Sigmund Freud first noted the curious fact that older memories are often remembered as if captured by a third person holding a camera, whereas more recent events tend to be remembered in the first person, as if through one's own eyes. It's as if things that happened to us become simply things that happened. Or as if, over time, the brain naturally turns episodes into facts.

How this process works at the level of neurons still remains a riddle. One well-supported hypothesis holds that our memories are nomadic. While the hippocampus is involved in their initial formation, their contents are ultimately held in long-term storage in the neocortex. Over time, as they are revisited and reinforced, memories are consolidated in a way that makes them impervious to erasure. They become entrenched in a network of cortical connections that allows them to exist independently of the hippocampus. All this raises a tantalizing question: Were EP's memories since 1950 completely obliterated when the virus ate its way through his medial temporal lobes, or did those memories just become inaccessible? Did the virus burn down half the house, or did it just throw away the key? We don't know.

It's thought that sleep plays a critical role in this process of consolidating our memories and drawing meaning out of them. Rats that have spent an hour running around a track apparently run through the same track in their sleep, and exhibit the same patterns of neural firings with their eyes closed as when they were learning the mazes in the first place. It has been suggested that the reason our own dreams so often feel like a surreal recombination of elements plucked from real life is that they are just the by-product of experiences slowly hardening into long-term memories.

Sitting with EP on the couch in his living room, I wonder if he still dreams. Of course, he can't tell, but I ask him anyway, just to see what he'll say. "From time to time," he tells me matter-of-factly, though his response is most certainly a confabulation. "But dreams are hard to remember."

We all come into the world as amnesics, and quite a few of us exit just the same. The other day, I was quizzing my three-year-old nephew about his second birthday party. Though the event took place more than a third of a lifetime ago, his recollections were surprisingly exact. He remembered the name of the young guitarist who had entertained him and his friends, and could recite some of the songs they had sung. He remembered the miniature drum set I'd given him as a gift. He remembered eating ice cream with cake. And yet, ten years from now, it is almost certain that he will remember none of this. the world as amnesics, and quite a few of us exit just the same. The other day, I was quizzing my three-year-old nephew about his second birthday party. Though the event took place more than a third of a lifetime ago, his recollections were surprisingly exact. He remembered the name of the young guitarist who had entertained him and his friends, and could recite some of the songs they had sung. He remembered the miniature drum set I'd given him as a gift. He remembered eating ice cream with cake. And yet, ten years from now, it is almost certain that he will remember none of this.

Until the age of three or four, almost nothing that happens to us leaves the sort of lasting impression that can be consciously recalled as an adult. The average age that people report having their earliest memory is three and a half, and those tend to be just blurry, fragmentary snapshots that are often false. How strange that during the period when a person is learning more rapidly than at any other point in his life-when one is learning to walk and talk and make sense of the world-so little of that learning is of the kind that is explicitly memorable.

Freud thought that infantile amnesia was a matter of adults repressing the hypers.e.xualized fantasies of early childhood, which only become shameful in later life. I'm not sure you could find too many psychologists who still cling to that interpretation. The more likely explanation for this strange early forgetting lies in the fact that our brains are maturing rapidly during the first couple years of life, with unused neural connections getting pruned back, and new connections constantly forming. The neocortex is not fully developed until about the third or fourth year, around the time that children start laying down permanent memories. Anatomy, however, may only tell part of the story. As infants, we also lack schema for interpreting the world and relating the present to the past. Without experience-and perhaps most important, without the essential organizing tool of language-infants lack the capacity to embed their memories in a web of meaning that will make them accessible later in life. Those structures only develop over time, through exposure to the world. The vital learning that we do during the first years of life is virtually entirely of the implicit, nondeclarative kind. In other words, everyone on earth has had some taste of EP's condition. And like EP, we've all forgotten what it's like.

I'm curious to see EP's unconscious, nondeclarative memory at work, so I ask him if he's interested in taking me on a walk around his neighborhood. He says, "Not really," so I wait and ask him again a couple minutes later. This time he agrees. We walk out the front door into the high afternoon sun and turn right-his decision, not mine. I ask EP why we're not turning to the left instead.

"I'd just rather not go that way. This is just the way I go. I don't know why," he says.

If I asked him to draw a map of the route he takes at least three times a day, he'd never be able to do it. He doesn't even know his own address, or (almost as improbably for someone from San Diego) which way the ocean is. But after so many years of taking the same walk, the journey has etched itself on his unconscious. His wife, Beverly, now lets him go out alone, even though a single wrong turn would leave him completely lost. Sometimes he comes back from his walks with objects he's picked up along the way: a stack of round stones, a puppy, somebody's wallet. He can never explain how they came into his possession.

"Our neighbors love him because he'll come up to them and just start talking to them," Beverly tells me. Even though he thinks he's meeting them for the first time, he's learned through force of habit that these are people he should feel comfortable with, and he interprets those unconscious feelings of comfort as a good reason to stop and say h.e.l.lo.

That EP has learned to like his neighbors without ever learning who they are points to how many of our basic day-to-day actions are guided by implicit values and judgments, independent of declarative memory. I wonder what other things EP has learned through force of habit. What other nondeclarative memories have continued to shape him over the decade and a half since he lost his declarative memory? Surely, he must still have desires and fears, emotions, and cravings-even if his conscious recollection of those feelings is so fleeting that he cannot recognize them for long enough to verbalize them.

I thought of my own self fifteen years ago, and how much I've changed in the same period. The me who exists today and the me who existed then, if put side by side, would look more than vaguely similar. But we are a completely different collection of molecules, with different hairlines and waistlines, and, it sometimes seems, little in common besides our names. What binds that me to this me, and allows me to maintain the illusion that there is continuity from moment to moment and year to year, is some relatively stable but gradually evolving thing at the nucleus of my being. Call it a soul, or a self, or an emergent by-product of a neural network, but whatever you want to call it, that element of continuity is entirely dependent on memory.

But even if we are at the mercy of our memories in establishing our ident.i.ties, it is clear that EP is much more than just a soulless golem. In spite of everything he's lost, there is still a person there, and a personality-a charming personality, in fact-with a unique perspective on the world. Even if a virus wiped clean his memories, it didn't completely wipe clean his personhood. It just left a hollow, static self that can never grow and can never change.

We cross the street and walk away from Beverly and Carol, leaving me alone with EP for the first time. He doesn't know who I am, or what I'm doing at his side, although he seems to sense that I'm there for some good reason. He looks at me and purses his lips, and I can see that he's searching for something to say. Rather than try to fill the empty silence, I let it linger for a moment to see where the discomfort might lead. I guess I'm hoping for some fleeting recognition of how odd it all must be, this scene without a prologue. But no such recognition comes, or if it does, EP never lets it surface. He is trapped, I realize, in the ultimate existential nightmare, utterly blind to the reality in which he lives. The impulse strikes me to help him escape, at least for a second. I want to take him by the arm and shake him. "You have a rare and debilitating memory disorder," I want to tell him. "The last fifty years have been lost to you. In less than a minute, you're going to forget that this conversation ever even happened." I imagine the horror that would descend upon him, the momentary clarity, the gaping emptiness that would open up in front of him, and close just as quickly. And then the pa.s.sing car or the singing bird that would snap him back into his oblivious bubble. But of course I don't do it.

"We've gone far enough," I tell him, and point him in the direction from which we came. We turn around and walk back down the street whose name he's forgotten, past the waving neighbors he doesn't recognize, to a home he doesn't know. In front of the house sits a car with tinted windows. We turn to look at our reflections. I ask EP what he sees.

"An old man," he says. "That's all."

FIVE.

THE MEMORY PALACE.

I had arranged to get together with Ed one last time before he headed back to Europe. He wanted to meet me in Central Park, which he had never seen before, and which he insisted was a vital stop on his tour of America. After taking in the bare late-winter trees and watching the runners do their midday laps around the Reservoir, we ended up at the southern end of the park, directly across the street from the Ritz-Carlton Hotel. It was a frigid and brutally windy afternoon-less than ideal conditions for thinking of any kind, much less memorizing. Nevertheless, Ed insisted that we remain outdoors. He handed me his cane and gamely clambered up one of the big boulders near the edge of the park, with what appeared to be some pain in his chronically arthritic joints. After scanning the horizon and commenting on the "perfect sublimity" of the spot, he invited me to join him on top of the rock. He had promised that he could teach me a few basic memory techniques in under an hour. It was hard to imagine we could brave the weather for any longer than that. had arranged to get together with Ed one last time before he headed back to Europe. He wanted to meet me in Central Park, which he had never seen before, and which he insisted was a vital stop on his tour of America. After taking in the bare late-winter trees and watching the runners do their midday laps around the Reservoir, we ended up at the southern end of the park, directly across the street from the Ritz-Carlton Hotel. It was a frigid and brutally windy afternoon-less than ideal conditions for thinking of any kind, much less memorizing. Nevertheless, Ed insisted that we remain outdoors. He handed me his cane and gamely clambered up one of the big boulders near the edge of the park, with what appeared to be some pain in his chronically arthritic joints. After scanning the horizon and commenting on the "perfect sublimity" of the spot, he invited me to join him on top of the rock. He had promised that he could teach me a few basic memory techniques in under an hour. It was hard to imagine we could brave the weather for any longer than that.

"I have to warn you," Ed said, as he delicately seated himself crosslegged, "you are shortly going to go from having an awed respect for people with a good memory to saying, 'Oh, it's all a stupid trick.' " He paused and c.o.c.ked his head, as if to see if that would in fact be my response. "And you will be wrong. It's an unfortunate phase you're just going to have to pa.s.s through."

He started his lesson with the most basic principle of all mnemonics: "elaborative encoding." Our memories weren't built for the modern world, he explained. Like our vision, our capacity for language, our ability to walk upright, and every other one of our biological faculties, our memories evolved through a process of natural selection in an environment that was quite different from the one we live in today.

Most of the evolution that shaped the primitive brains of our prehuman ancestors into the linguistic, symbolic, neurotic modern brains that serve us (sometimes poorly) today took place during the Pleistocene, an epoch which began about 1.8 million years ago and only ended ten thousand years ago. During that period-and in a few isolated places, still to this day-our species made its living as huntergatherers, and it was the demands of that lifestyle that sculpted the minds we have today.

Much as our taste for sugar and fat may have served us well in a world of scarce nutrition, but is now maladaptive in a world of ubiquitous fast food joints, our memories aren't perfectly adapted for our contemporary information age. The tasks that we often rely on our memories for today simply weren't relevant in the environment in which the human brain evolved. Our ancestors didn't need to recall phone numbers, or word-for-word instructions from their bosses, or the Advanced Placement U.S. history curriculum, or (because they lived in relatively small, stable groups) the names of dozens of strangers at a c.o.c.ktail party.

What our early human and hominid ancestors did did need to remember was where to find food and resources, and the route home, and which plants were edible and which were poisonous. Those are the sorts of vital memory skills that they depended on every day, and it was-at least in part-in order to meet those demands that human memory evolved as it did need to remember was where to find food and resources, and the route home, and which plants were edible and which were poisonous. Those are the sorts of vital memory skills that they depended on every day, and it was-at least in part-in order to meet those demands that human memory evolved as it did.

The principle underlying all memory techniques is that our brains don't remember all types of information equally well. As exceptional as we are at remembering visual imagery (think of the two-picture recognition test), we're terrible at remembering other kinds of information, like lists of words or numbers. The point of memory techniques is to do what the synasthete S did instinctually: to take the kinds of memories our brains aren't good at holding on to and transform them into the kinds of memories our brains were built for.

"The general idea with most memory techniques is to change whatever boring thing is being inputted into your memory into something that is so colorful, so exciting, and so different from anything you've seen before that you can't possibly forget it," Ed explained to me between breaths into his clenched fists. "That's what elaborative encoding is. In a moment, we're going to do this with a list of words, which is just a sort of general exercise for getting ahold of the techniques. Then you're going to be able to move on to numbers, playing cards, and then, from there, to complex concepts. Basically, when we're done with you, you're going to be able to learn anything you want to, really."

Ed recounted how on a recent visit to Vienna, he and Lukas had partied until dawn the night before Lukas's biggest exam of the year, and only stumbled home just before sunrise. "Lukas woke up at noon, learned everything for the exam in a memory blitz, and then pa.s.sed it," said Ed. "When you're that effective at learning, it's a bit of a temptation to not bother oneself with feelings of academic guilt until the last possible moment. Lukas has figured out that effort is a rather vulgar exercise."

Ed tucked his curls behind his ears, and asked me what I wanted to memorize first. "We could start by learning something useful, like the Egyptian pharaohs or the terms of the American presidents," he offered. "Or perhaps a Romantic poem? We could do the geological epochs, if you'd like."

I laughed. "That all sounds very very useful." useful."

"We could quickly learn all the American football winners for the last century or so, or the point averages of the top baseball stars, if you'd like."

"Do you know-really know-all the winners of the Super Bowl?" I asked.

"Well, no, I don't. I prefer cricket. But I'd be happy to teach them to you. That's the point: We can quickly learn anything with these techniques. Look, you tempted or not?"

"I'm tempted."

"Well, I suppose the most obvious, practical use of this technique is the mastery of one's to-do list. Do you keep a to-do list?"

"At home, yes. Sort of. From time to time."

"I see. Well, I keep a to-do list in my memory at all times. We'll use mine."

Ed asked for a piece of paper, which he then scribbled a few words on. He handed it back to me with a mischievous smirk. It was a list of fifteen items. "Just a few things I've got to get done around town before I head upstate for a party a friend of mine is throwing," he said.

I read the list aloud: Pickled garlic Cottage cheese Salmon (peat-smoked if poss.) Six bottles of white wine Socks (x3) Three hula-hoops (spare?) Snorkel Dry ice machine E-mail Sophia Skin-toned cat suit Find Paul Newman film-Somebody Up There Likes Me Elk sausages??

Megaphone and director's chair Harness and ropes Barometer "This list is from your memory?" I asked incredulously.

"From my memory it came. Into your memory it shall go," said Ed.

"And this is serious?"

"Well, I'm not sure if I'll be able to find everything on it. Do you have cottage cheese in New York?"

"I'm a little more concerned about the elk sausages and the skin-toned cat suit," I told him. "And besides, aren't you leaving town to go back to England tomorrow?"

"Yes, well, I'm prepared to accept that many of these items aren't absolutely absolutely necessary." He winked. "The point of this exercise, however, is that you are going to commit this list to memory." necessary." He winked. "The point of this exercise, however, is that you are going to commit this list to memory."

Ed told me that by learning the techniques he was about to teach, I would be installing myself in a "proud tradition of mnemonists." That proud tradition began, at least according to legend, in the fifth century B.C. with the poet Simonides of Ceos standing in the rubble of the great banquet hall collapse in Thessaly. As the poet closed his eyes and reconstructed the crumbled building in his imagination, he had an extraordinary realization: He remembered where each of the guests at the ill-fated dinner had been sitting. Even though he had made no conscious effort to memorize the layout of the room, it had nevertheless left a durable impression upon his memory. From that simple observation, Simonides reputedly invented a technique that would form the basis of what came to be known as the art of memory. He realized that if it hadn't been guests sitting at the banquet table, but rather something else-say, every great Greek dramatist seated in order of their dates of birth-he would have remembered that instead. Or what if, instead of banquet guests, he saw each of the words of one of his poems arrayed around the table? Or every task he needed to accomplish that day? Just about anything that could be imagined, he reckoned, could be imprinted upon one's memory, and kept in good order, simply by engaging one's spatial memory in the act of remembering. To use Simonides' technique, all one has to do is convert something unmemorable, like a string of numbers or a deck of cards or a shopping list or Paradise Lost Paradise Lost, into a series of engrossing visual images and mentally arrange them within an imagined s.p.a.ce, and suddenly those forgettable items become unforgettable.

Virtually all the nitty-gritty details we have about cla.s.sical memory training-indeed, nearly all the memory tricks in the mental athlete's a.r.s.enal-were first described in a short, anonymously auth.o.r.ed Latin rhetoric textbook called the Rhetorica ad Herennium Rhetorica ad Herennium, written sometime between 86 and 82 B.C. It is the only truly complete discussion of the memory techniques invented by Simonides to have survived into the Middle Ages. Though the intervening two thousand years have seen quite a few innovations in the art of memory, the basic techniques have remained fundamentally unchanged from those described in the Ad Herennium Ad Herennium. "This book is our bible," Ed told me.

Ed reads both Latin and ancient Greek (as well as speaking French and German fluently) and fancies himself an amateur cla.s.sicist. The Ad Herennium Ad Herennium was to be the first of several ancient texts he pressed upon me. Before I sampled Tony Buzan's expansive oeuvre (he's auth.o.r.ed or coauth.o.r.ed over 120 books) or any of the self-help books put out by the top mental athletes, Ed wanted me to start my investigation with the cla.s.sics. In addition to the was to be the first of several ancient texts he pressed upon me. Before I sampled Tony Buzan's expansive oeuvre (he's auth.o.r.ed or coauth.o.r.ed over 120 books) or any of the self-help books put out by the top mental athletes, Ed wanted me to start my investigation with the cla.s.sics. In addition to the Ad Herennium Ad Herennium, there would be translated excerpts of Quintilian's Inst.i.tutio Oratoria Inst.i.tutio Oratoria and Cicero's and Cicero's De Oratore De Oratore for me to read, followed by a collection of medieval writings on memory by Thomas Aquinas, Albertus Magnus, Hugh of St. Victor, and Peter of Ravenna. for me to read, followed by a collection of medieval writings on memory by Thomas Aquinas, Albertus Magnus, Hugh of St. Victor, and Peter of Ravenna.

The techniques introduced in the Ad Herennium Ad Herennium were widely practiced in the ancient world. In fact, in his own writings on the art of memory, Cicero says that the techniques are so well known that he felt he didn't need to waste ink describing them in detail (hence our reliance on the were widely practiced in the ancient world. In fact, in his own writings on the art of memory, Cicero says that the techniques are so well known that he felt he didn't need to waste ink describing them in detail (hence our reliance on the Ad Herennium Ad Herennium). Once upon a time, every literate person was versed in the techniques Ed was about to teach me. Memory training was considered a centerpiece of cla.s.sical education in the language arts, on par with grammar, logic, and rhetoric. Students were taught not just what to remember, but how to remember it.

In a world with few books, memory was sacrosanct. Just look at Pliny the Elder's Natural History Natural History, the first-century encyclopedia that chronicled all things wondrous and useful for winning bar bets in the cla.s.sical world, including the most exceptional memories then known to history. "King Cyrus could give the names of all the soldiers in his army," Pliny reports. "Lucius Scipio knew the names of the whole Roman people. King Pyrrhus's envoy Cineas knew those of the Senate and knighthood at Rome the day after his arrival ... A person in Greece named Charmadas recited the contents of any volumes in libraries that anyone asked him to quote, just as if he were reading them." There are plenty of reasons not to take everything Pliny says at face value (he also reported the existence of a race of dog-headed people in India) but the sheer volume of anecdotes about extraordinary memories in the cla.s.sical world is itself telling. Seneca the Elder could repeat two thousand names in the order they'd been given to him. St. Augustine tells of a friend, Simplicius, who could recite Virgil by heart-backward. (That he could recite it forward seems to have been unremarkable.) A strong memory was seen as the greatest virtue since it represented the internalization of a universe of external knowledge. "Ancient and medieval people reserved their awe for memory. Their greatest geniuses they describe as people of superior memories," writes Mary Carruthers, the author of two books on the history of memory techniques. Indeed, the single most common theme in the lives of the saints-besides their superhuman goodness-is their often extraordinary memories.

The Ad Herennium Ad Herennium's discussion of memory-"that treasure-house of inventions and the custodian of all parts of rhetoric"-is actually quite short, about ten pages embedded in a far longer treatise on rhetoric and oration. It begins by making a distinction between natural memory and artificial memory: "The natural memory is that memory which is embedded in our minds, born simultaneously with thought. The artificial memory is that memory which is strengthened by a kind of training and system of discipline." In other words, natural memory is the hardware you're born with. Artificial memory is the software you run on your hardware.

Artificial memory, the anonymous author continues, has two basic components: images and places. Images represent the contents of what one wishes to remember. Places-or loci, as they're called in the original Latin-are where those images are stored.

The idea is to create a s.p.a.ce in the mind's eye, a place that you know well and can easily visualize, and then populate that imagined place with images representing whatever you want to remember. Known as the "method of loci" by the Romans, such a building would later come to be called a "memory palace."

Memory palaces don't necessarily have to be palatial-or even buildings. They can be routes through a town-as they were for S-or station stops along a railway, or signs of the zodiac, or even mythical creatures. They can be big or small, indoors or outdoors, real or imaginary, so long as there's some semblance of order that links one locus to the next, and so long as they are intimately familiar. The four-time U.S. memory champion Scott Hagwood uses luxury homes featured in Architectural Digest Architectural Digest to store his memories. Dr. Yip Swee Chooi, the effervescent Malaysian memory champ, used his own body parts as loci to help him memorize the entire 56,000-word, 1,774-page Oxford Chinese-English dictionary. One might have dozens, hundreds, perhaps even thousands of memory palaces, each built to hold a different set of memories. to store his memories. Dr. Yip Swee Chooi, the effervescent Malaysian memory champ, used his own body parts as loci to help him memorize the entire 56,000-word, 1,774-page Oxford Chinese-English dictionary. One might have dozens, hundreds, perhaps even thousands of memory palaces, each built to hold a different set of memories.

In Australia and the American Southwest, Aborigines and Apache Indians independently invented forms of the loci method. But instead of using buildings, they relied on the local topography to plot their narratives, and sang them across the landscape. Each hillock, boulder, and stream held a part of the story. "Myth and map became coincident," says John Foley, a linguistic anthropologist at the University of Missouri who studies memory and oral traditions. One of the tragic consequences of embedding narrative into the landscape is that when Native Americans had land taken from them by the U.S. government, they lost not only their home but their mythology as well.

"The thing to understand, Josh, is that humans are very, very good at learning s.p.a.ces," Ed remarked from his perch on the boulder. "Just to give an example, if you are left alone for five minutes in someone else's house you've never visited before, and you're feeling energetic and nosy, think about how much of that house could be fixed in your memory in that brief period. You'd be able to learn not just where all the different rooms are and how they connect with each other, but their dimensions and decoration, the arrangement of their contents, and where the windows are. Without really noticing it, you'd remember the whereabouts of hundreds of objects and all sorts of dimensions that you wouldn't even notice yourself noticing. If you actually add up all that information, it's like the equivalent of a short novel. But we don't ever register that as being a memory achievement. Humans just gobble up spatial information."

The principle of the memory palace, he continued, is to use one's exquisite spatial memory to structure and store information whose order comes less naturally-in this case, Ed's to-do list. "What you're going to find is that in the same way as it's impossible to get confused about the order of rooms in that house, it will be equally obvious that immediately after I locate three hula hoops, a snorkel, and a dry ice machine, my next task will be e-mailing my friend Sophia."

The crucial thing was to choose a memory palace with which I was intimately familiar. "For your first memory palace, I'd like you to use the house you grew up in, since that's a s.p.a.ce you're likely to know very well," Ed said. "We're going to array the items of my to-do list one by one along a route that will snake around your childhood home. When it comes time to recall the list, all you will need to do is retrace the steps we're about to take in your imagination. The hope is that all the objects you're about to memorize will pop back into mind. Now, tell me, is your childhood home a bungalow?"

"More of a two-story brick house," I said.

"Does it have a cute postbox at the end of the driveway?"

"No. Why?"

"Shame. That would be an excellent first locus at which to deposit an image of the first item on our to-do list. But that's okay. We can start at the foot of the driveway. I want you to close your eyes and try to visualize in as much detail as possible a large bottle of pickled garlic standing right where the car should be parked."

I wasn't entirely sure what I was supposed to be visualizing. "What is pickled garlic? Is that, like, an English delicacy?" I asked.

"Um, no, it's just the sort of snack one brings along for a weekend out in the mountains." He flashed another impish grin. "Now, it's very important to try to remember this image multisensorily." The more a.s.sociative hooks a new piece of information has, the more securely it gets embedded into the network of things you already know, and the more likely it is to remain in memory. Just as S spontaneously and involuntarily turned every sound that pa.s.sed through his ears into a chorus of colors and smells, the author of the Ad Herennium Ad Herennium urged his readers to do the same with every image they wanted to remember. urged his readers to do the same with every image they wanted to remember.

"It's important that you deeply process that image, so you give it as much attention as possible," Ed continued. "Things that grab our attention are more memorable, and attention is not something you can simply will. It has to be pulled in by the details. By laying down elaborate, engaging, vivid images in your mind, it more or less guarantees that your brain is going to end up storing a robust, dependable memory. So try to imagine the pleasant smell of the pickled garlic, and exaggerate its proportions. Imagine tasting it. Really let the flavor roll around on your tongue. And make sure you see yourself doing this at the foot of your driveway." If I didn't know what pickled garlic was, I was even less sure of how it tasted. Nevertheless, I imagined a large bottle of the stuff standing proudly at the foot of my parents' driveway.

(I'd encourage you, reader, to do the same along with me. Try imagining a bottle of pickled garlic at the foot of your own driveway, or if you don't have a driveway, someplace else outside your home. Really try to visualize it.) "Now that you've installed a complete multisensorial picture of pickled garlic, we're going to walk up the path to your home and visualize the next item on our to-do list at the front door. It's cottage cheese. I want you to close your eyes and see an enormous wading-pool-size tub of cottage cheese. Have you got it?

"I think so."

(Have you?) "Now I want you to imagine Claudia Schiffer swimming in this tub of cottage cheese. I want you to imagine her swimming in the buff, and dripping with dairy. Are you picturing this? I don't want you to miss any of the details here."

The Ad Herennium Ad Herennium advises readers at length about creating the images for one's memory palace: the funnier, lewder, and more bizarre, the better. "When we see in everyday life things that are petty, ordinary, and ba.n.a.l, we generally fail to remember them, because the mind is not being stirred by anything novel or marvelous. But if we see or hear something exceptionally base, dishonorable, extraordinary, great, unbelievable, or laughable, advises readers at length about creating the images for one's memory palace: the funnier, lewder, and more bizarre, the better. "When we see in everyday life things that are petty, ordinary, and ba.n.a.l, we generally fail to remember them, because the mind is not being stirred by anything novel or marvelous. But if we see or hear something exceptionally base, dishonorable, extraordinary, great, unbelievable, or laughable, that that we are likely to remember for a long time." we are likely to remember for a long time."

The more vivid the image, the more likely it is to cleave to its locus. What distinguishes a great mnemonist, I was learning, is the ability to create these sorts of lavish images on the fly, to paint in the mind a scene so unlike any that has been seen before that it cannot be forgotten. And to do it quickly. Which is why Tony Buzan tells anyone who will listen that the World Memory Championship is less a test of memory than of creativity.

When forming images, it helps to have a dirty mind. Evolution has programmed our brains to find two things particularly interesting, and therefore memorable: jokes and s.e.x-and especially, it seems, jokes about s.e.x. (Do you remember what Rhea Perlman and Manute Bol were doing on the first page of this book?) Even memory treatises from comparatively prudish eras make this point. Peter of Ravenna, author of the most famous memory textbook of the fifteenth century, first asks the pardon of chaste and religious men before revealing "a secret which I have (through modesty) long remained silent about: if you wish to remember quickly, dispose the images of the most beautiful virgins into memory places; the memory is marvelously excited by images of women."