The common experience is, that the man fits himself as well as he can to the customary details of that work or trade he falls into, and tends it as a dog turns a spit. Then he is part of the machine he moves; the man is lost.
A lot of people change for good. Some people just fall off. Just trying to progress in anything, no matter what you're doing, I feel like any progression you make... some people aren't gonna be around you that were around you.
We are in a survival mentality, and that's hard-wired into our humanity, because we are the winners of an evolutionary struggle of millions and millions and millions of years.