In this post, I wrote:

I don’t think I have too many ‘headspace’ or ‘immersive’ characters to begin with. Of those, it’s unusual for me to have one that’s notably opposite from myself — in the cases where that’s happened (and I can think of three) they reflected some strong negative emotion I was feeling toward the game itself.

That actually provides me with a very strong indicator that I can use to analyze myself when I’m making up a character for a game — if I’m making up someone who’s really a negative of myself, it would seem to indicate that I’m reflecting some negative thing in myself out on the paper, which in turn indicates that I’m feeling some kind of negative emotion toward the game in question, apparently subconsciously.
Recognizing that, I can stop and figure out what that is, and maybe do something about it.
(Granted, this is a hypothetical practice/benefit at this point.)