H e was six-feet-two, and on a good day he weighed 200 pounds. He wore granny glasses with a head scarf, points knotted at the back, a look that was both pirate-like and housewife-ish. He always wore his hair long. He had dark eyes, soft voice, caveman chin, a lovely, peak-lipped mouth that was his best feature. He walked with an ex-athlete's saunter, a roll from the heels, as if anything physical was a pleasure. David Foster Wallace worked surprising turns on nearly everything: novels, journalism, vacation. His life was an information hunt, collecting hows and whys. "I received 500,000 discrete bits of information today," he once said, "of which maybe 25 are important. My job is to make some sense of it." He wanted to write "stuff about what it feels like to live. Instead of being a relief from what it feels like to live." Readers curled up in the nooks and clearings of his style: his comedy, his brilliance, his humaneness.

His life was a map that ends at the wrong destination. Wallace was an A student through high school, he played football, he played tennis, he wrote a philosophy thesis and a novel before he graduated from Amherst, he went to writing school, published the novel, made a city of squalling, bruising, kneecapping editors and writers fall moony-eyed in love with him. He published a thousand-page novel, received the only award you get in the nation for being a genius, wrote essays providing the best feel anywhere of what it means to be alive in the contemporary world, accepted a special chair at California's Pomona College to teach writing, married, published another book and, last month, hanged himself at age 46.

"The one thing that really should be said about David Foster Wallace is that this was a once-in-a-century talent," says his friend and former editor Colin Harrison. "We may never see a guy like this again in our lifetimes — that I will shout out. He was like a comet flying by at ground level."

His 1996 novel, Infinite Jest, was Bible-size and spawned books of interpretation and commentary, like Understanding David Foster Wallace — a book his friends might have tried to write and would have lined up to buy. He was clinically depressed for decades, information he limited to family and his closest friends. "I don't think that he ever lost the feeling that there was something shameful about this," his father says. "His instinct was to hide it."

After he died on September 12th, readers crowded the Web with tributes to his generosity, his intelligence. "But he wasn't Saint Dave," says Jonathan Franzen, Wallace's best friend and the author of The Corrections. "This is the paradox of Dave: The closer you get, the darker the picture, but the more genuinely lovable he was. It was only when you knew him better that you had a true appreciation of what a heroic struggle it was for him not merely to get along in the world, but to produce wonderful writing."

D avid grew up in Champaign, Illinois. His father, Jim, taught philosophy at the University of Illinois. His mother, Sally, taught English at a local community college. It was an academic household — poised, considerate — language games in the car, the rooms tidy, the bookcase the hero. "I have these weird early memories," Wallace told me during a series of interviews in 1996. "I remember my parents reading Ulysses out loud to each other in bed, holding hands and both lovin' something really fiercely." Sally hated to get angry — it took her days to recover from a shout. So the family developed a sort of interoffice conflict mail. When his mother had something stern to say, she'd write it up in a letter. When David wanted something badly — raised allowance, more liberal bedtime — he'd slide a letter under his parents' door.

David was one of those eerie, perfect combinations of two parents' skills. The titles of his father's books — Ethical Norms, Particular Cases — have the sound of Wallace short-story titles. The tone of his mother's speaking voice contains echoes of Wallace's writing voice: Her textbook, Practically Painless English, sounds like a Wallace joke. She uses phrases like "perishing hot" for very hot, "snoof" for talking in your sleep, "heave your skeleton" for go to bed. "David and I both owe a huge debt to my mother," says his sister, Amy, two years younger. "She has a way of talking that I've never heard anywhere else."

David was, from an early age, "very fragile," as he put it. He loved TV, and would get incredibly excited watching a program like Batman or The Wild Wild West. (His parents rationed the "rough" shows. One per week.) David could memorize whole shows of dialogue and predict, like a kind of plot weatherman, when the story was going to turn, where characters would end up. No one saw or treated him as a genius, but at age 14, when he asked what his father did, Jim sat David down and walked him through a Socratic dialogue. "I was astonished by how sophisticated his understanding was," Jim says. "At that point, I figured out that he really, really was extraordinarily bright."