Ten years out of college and A.J. Jacobs felt like he was getting dumber by the day. A showbiz journalist for publications like Entertainment Weekly and Esquire, his intellectual feats consisted of interviews with C-list celebrities and critiques of new sitcoms.

"My IQ took a belly flop," says Jacobs. "I forgot all about Homer the Greek poet and I knew way too much about Homer Simpson."

So Jacobs embarked on a quest: read the entire Encyclopedia Britannica—all 32 volumes, 33,000 pages and 44 million words. It took 18 months and every moment of his spare time, but he finished the job. Then he went on to write a hilarious book about the experience, titled The Know-It-All: One Man's Humble Quest to Become the Smartest Person in the World.

Did he really become a genius? "I'm no Albert Einstein," says Jacobs. "I'm not even Alfred Einstein, who, by the way, was Albert's distant cousin and a noted music historian with his very own write-up in the Britannica."

Know-it-all, indeed.

What's the most important information you learned from the encyclopedia?
I really wanted there to be one piece of information that would save my life. Like, I wanted to be stranded in the Arctic and know that I couldn't eat polar bear livers because they have a toxic level of vitamin A. So far there's been nothing like that. But I did learn some wisdom that changed my perspective on life. If you look across the sweep of human history, you see that people are capable of both horrible things and great things. In the end, the great outweighs the horrible so that gave me hope and made me a more optimistic person.

Do you think learning too much information can clutter up your mind and actually make you dumber?
A lot of my book is about the relationship between information and intelligence. They're not the same thing—just knowing thousands of facts doesn't make you smarter—but they are related. Facts and intelligence are like cousins. The metaphor I use is that facts are the fuel and intelligence is the engine. The more facts you have, the more fuel you have for your engine and the better you're able to make connections between things and come up with creative solutions.

When did you first realize you were an Inforati?
Information has been my first love for as long as I can remember. I was reading trivia books from the time I was a kid. I'm even holding one right now, called Fascinating Facts. Check it out—did you know that in 1740 a cow was found guilty of sorcery in France and publicly hanged? Some people collect stamps or coins. People like me, who are obsessed with information, collect facts. Finding a particularly obscure fact is like owning a great stamp that no one else has.

What are your top information resources?
I still use the Britannica quite a lot, though I mostly read the electronic version and rarely pick up the old paper-and-ink version. Did you know that the explorer, Ernest Shackleton, took the entire ninth edition with him to Antarctica and ended up using it for kindling to keep from freezing? You can't do that with your computer without choking on toxic fumes. I also love Wikipedia, which is a remarkable tool in terms of the ease and access of information. But I would never rely solely on Wikipedia for information because I think there are still a few problems with accuracy.

Who's your information hero?
The German writer, Johann Wolfgang von Goethe, because he was the ultimate Renaissance man. He was a critic, journalist, lawyer, painter, theater manager, statesman, educationalist, soldier, astrologer, novelist, philosopher, alchemist, songwriter, botanist, biologist, color theorist, mine inspector, military-uniform designer, and supervisor of irrigation schemes. Back in the 18th century you could be an expert in all sorts of subjects. Now it's so much harder, because the depth of information for any particular topic is so deep. I guess I was born in the wrong century.