Why do women hate you after breakup

As far as I know we left on fair terms, not exactly bitter hate but once we’ve been gone from each other for a while, every time they see me they hate me they try every little thing to get me down… why? It’s not like I even initiated the breakup she did it herself and yet she’s still sour with me. I gave her the best I could and she’s still mad at me… WHAT HAPPENED!?