You live the life of a flight school student- it's kind of like being in college again, except you're getting paid to be there. Some people get jobs while they're not in a class, but once you start a phase of flight school you're sole focus is to learn to be a good aviator.
And no, there are plenty of aviators who get out at the end of their commitment and do other things in life. Some go to the airlines, some go to graduate school, law school, med school, so go back to the family business, some stop flying altogether. This may blow your mind as you're trying to get into the club, but there are a lot of folks who are happy and ready to leave when their commitment is up. What gets you in at 24 doesn't keep you in at 34.