The New York Times' Bill Keller

Why?
Of his career in journalism, Keller says, "Some simply love to write. Some are curious. Some want to change the world. Some seek adventure. Some like seeing their names in print. Some want to witness history. I plead at least a little guilty to all of those motives, but what has always appealed to me most was puzzling things out — taking a complicated situation, investigating and studying it until I thought I understood it, then explaining it as best I could. If I hadn't been a journalist, I'd probably have been a teacher."