I have a cousin who became a fully qualified cardiac surgeon at 30 years old. Whenever I ask him about his job, he get excited and it's very apparent that he enjoys what he does. I must admit that he does somewhat have a weird sense of humor though. At 34 now, he's already married and has 2 children, so there's definitely a "life" behind a surgeon.
However, his life is quite erratic. Every now and then (quite often actually), he gets a emergency call from his hospital and has to rush off to work regardless of the time, which can be extremely stressful for some people especially if they're in the middle of something.
P.S. Everyone gets impressed by him whenever a cake needs to be cut. He seems to do it so effortlessly and the pieces are always perfectly the same! There was once that he miss-cut the cake and wondered aloud that if that was a real person, that guy would've been dead...