In college, a few years ago, I was head over heels in love with someone. She was incredible to me... at first. Then she started treating me really badly. Caught her with another dude, etc. Eventually it ended.
Went on a massive self-improvement stint for YEARS. Got into incredible shape, learned new skills, got an awesome car, got into law school, starred in a few independent movies (low budget student stuff, nothing any good), etc.
I saw her again during our last year of college. We hit it off again and I was again in love with her. I couldn't let go of the way she treated me before, though. I started acting like an a$$hole to her, and it ended again.
I guess in retrospect I don't know if it was completely unjustified, but I do know that if nothing else, I miss the feeling that I had with her. If some guys have that one girl that "ruins" them and turns them into some sort of player, she'd be it for me beyond any shadow of a doubt. I never talk about her to anyone, though. She runs to my mind quite often, though.