On the one hand that's some admirable persistence right there.. on the other I don't know.. how would you feel if your doctor had been rejected 14 times from med school before getting his degree?
I think the astronauts are more patients than doctors. They are test subjects. Every move in space is carefully planned by committees on the ground. No doubt it is a demanding job requiring all sorts of skills, but it isn't the same as a surgeon. Absent some worst case scenarios, responsibility and decision making is far more shared.
Astronauts are some of the most highly trained people on the planet.