I used to think I had ambition... but now I'm not so sure. It may have been only discontent. They're easily confused.
I remember Agassi playing Federer in Basel, Switzerland in 1998, and Andre was already saying at that time that Federer would be tough. Usually at the time players are 17, you can see if they will be great.
American science is much more organized, much more hierarchical than British science has been.