How did Theo Epstein become GM?

[Vincent]

I don't know anything about this guy. He's the GM (or baseball's equivalent) of the Bosox, and he's really young. How does someone so young get that job? Was he a former player who got injured? What are his credentials and connections that assisted him into landing that job?

I'm curious because I have dreams of being GM of an NBA team like every other sports fan out there.