"You're Getting Old"

In South Park episode "You're Getting Old", Stan starts feeling and seeing more and more things as sh*t, and the doctor tells him it's a condition called "being a cynical asshole". I thought maybe it was some healthy self-reflection on the parts of Matt and Trey, but I am not sure they are capable of that.
I might also think it reflects on some aspect of myself, but then I'd have been getting old since I was about ten. Oh sh*t, it happened to Stan after his tenth birthday! Oh no, no, block it out, block it out!!