Excerpt from The Know-It-All by A. J. Jacobs, plus links to reviews, author biography & more

Even seeing other people get brain damage flustered me. When I was eleven, I went to the movie Hair with my mother at New York's Ziegfeld Theater, and was horrified to watch Treat Williams and his unshowered cohorts smoking pot in a Central Park tunnel. I could almost hear their poor brain cells scream for mercy. "Can we go?" I asked my mom before the first "Aquarius" refrain. "I don't feel so good."

Drug-addled musicals aside, the thing that really unhinged me was car rides. My fourth-grade biology teacher told us that the carbon monoxide produced by cars can cause brain damage. That was it, just a throwaway line inserted into a lecture on mammalian bloodstreams. But to me, carbon monoxide became the number one enemy, my white whale, the Joab to my Absalom.

I became a window Nazi. A window had to be cracked at all times so that my brain could get fresh oxygen to dilute that nefarious carbon monoxide. It could be forty below zero and we could be driving through Vostok Station; I'd still roll down the glass in the backseat of the Plymouth Valiant.

"Can you please shut that? It's really cold," said Mom.

"Just a little fresh air, Mom," I'd say.

"That fresh air is freezing my eyelids together."

"Roll up the window, A.J.," my dad said.

I'd roll it up. I'd wait about two minutes, till the conversation had drifted to some other topic, like which fast food chain most deserved our patronage, then I'd slowly -- in barely noticeable spurts -- lower the window again.

"Dammit, A.J.!" my mom would say, as her lower lip turned cobalt blue. "Please put up the window."

I was smart enough to know that I shouldn't tell anyone the reason I needed that icy air. No need to spill the secret that I was the genius of all geniuses, the Leonardo da Vinci of the 1980s. That would just inspire envy and skepticism. So I'd just stare at the closed window and stew. If ten minutes went by without my lungs getting fresh air, I panicked. I needed to make sure the monoxide hadn't eaten my cranium. For some reason, and this continues to baffle me, I thought the best way to test whether my mind was still in peak form was to create new and bizarre racquet sports. That was my homespun IQ test. So I made up racquet sports involving big racquets, tiny racquets, balls the size of refrigerators, balls the size of pencil erasers. There were racquet sports involving garage doors, bathroom sinks, and telecommunications satellites. Strange, I know. But it made me feel better.

Not counting my vigilance against brain damage, there were plenty of other strains associated with being the smartest boy in the world. It was a huge responsibility, nurturing this amazing organ of mine. I knew someday soon I'd have to invent something, cure something, or write something of grand significance. I knew I should be feeding my mind the highest-quality nourishment, like physics textbooks or Dostoyevsky, but instead I was keeping it on a starvation diet by watching Gilligan's Island reruns. Even back then, I had trouble resisting pop culture's pull. I felt guilty every time I watched those hapless castaways. Not that it stopped me, but I just couldn't enjoy Thurston Howell's lockjaw one-liners like my lucky bastard classmates with their slightly above-average intelligence.

I remember the day I decided I wasn't the smartest boy in the world. I was watching TV -- not sitcom reruns, for once, but a documentary on Hasidic Jews. The footage showed a room of young Hasidic boys about the same age as I was, at their desks, their noses buried in books. The narrator intoned that these boys studied for sixteen hours a day. I was blown away. Sixteen hours a day! My God. Even though I knew I had the initial advantage of the highest-quality brain, these boys studied so much, they must have pulled several lengths ahead of me in the intelligence horse race. I just couldn't compete with sixteen hours a day. This was an immense relief. A whole new day. I started watching Gilligan and Ginger and all the rest with impunity.

From The Know-It-All by A.J. Jacobs.  Pages 7-30 of the hardcover edition.  Copyright © 2004 by A.J. Jacobs