I need a few quitters

I'm trying to assemble a list of a dozen or so people who have achieved the status of 'best in the world,' but quit something else in order to get there. Example: Scott Adams, creator of Dilbert, was a mid-level cubicle-dwelling drone at PacBell, and would be to this day if he hadn't quit. Suze Orman was a broker at Prudential-Bache before she quit and created an empire.

If you know some great examples of people who have quit and been glad they did, I'd love to hear them (unfamous examples welcome). My top 10 favorite submissions get a free signed copy of the Dip, which I'll mail out next week. Send your idea by email, don't forget your mailing address.

[I got a TON of great entries. I'm processing them now. You can send more if you like, but chances of winning are close to zero. Thanks, guys.]