The chances of a high school student eventually becoming first violin for the Boston Philharmonic: one in a million.
The chances of a high school student eventually playing basketball in the NBA? About the same.
In fact, the chances of someone growing up and getting a job precisely like yours, whatever it is, are similarly slim. (Head of development at an ad agency, director of admissions for a great college... you get the idea). Every good gig is a long shot, but in the end, a lot of talented people get good gigs. The odds of being happy and productive and well compensated aren't one in a million at all, because there are many good gigs down the road. The odds are only slim if you pick precisely one job.