Lyric discussion by merovak 

Cover art for Sour Girl lyrics by Stone Temple Pilots

i agree with the growth part - but i think it also has signs of "regression" on the guys part...

when these people met, she was "sour" he was "happy" (at least on the surface: I was a superman but looks are decieving)

during the course of the relationship he built her up as a person while she seems to wear him down. it was probably this regression on his part that led to their splitting....

so.. when they went their separate ways - she was a better person while he was a wreck - they both came full circle...kinda like real relationships during those teenage years