1. Be really smart
2. Be willing to do something that's deadly boring to most smart people
Me? I'm a scientist. I'm not gonna write your goddamn binary tree pricing algorithm or remove your varicose veins or argue about some dull point of legal text in court. But I'm sure I'd be a lot richer if I did.
(In other news, man, those grapes sure look sour, I'm glad I can't reach 'em.)