Why would an old girlfriend who loved me then treat me like crap now?

I tried to reconnect with an old girlfriend. Its been several years. She loved me and I loved her back then. We parted ways on reasonably decent cirstances. There perhaps were some hard feelings but it was otherwise amicable. What Im saying is that there is no reason for her to hate me. I dont expect her to love me still, of course, and Im not asking for that... but surely if you love someone once you could still find a place for them in your heart now, right? Does she hate me because she cares so much? Or what? There is no reason for bitter hateful emotions. We broke up so many times now, I dont even remember who broke up with who this last time. We have gone into and out of relationships with one another so many times. We kept coming back to one another so many times over the years. And that is over I know. But I still care enough to be friends with her. The break up was uneventful and peaceful and perhaps even mutual, but she treats me like Im worse than crap now and is unwilling to put an iotas effort into rekindling a friendship. How should this make me feel?