I used to get angry when I heard stuff like that. Now I just say "Thank you".
Thank you for letting me know that you're shallow up front, before we signed any legal papers.
Thank you for being a flake before I actually had to rely on you more than I needed to today.
Thank you for letting me know you are NOT the one, and for giving me that extra little push to find someone that thinks I'm wonderful.
And now I have a good one!
So a big Thank You to all of my exes that were asses. And my boyfriend thanks you too.