Why do i want him back? dammit.?

he dumped me. then wanted me back. then dumped me again after i found out he had another girl. i shouldn't be wanting him back should i? but i can't help it. i didn't call him at all but after he called me out of the blue just to congratulate me on an achievement, i find myself hoping for him back and end the hellish pit of pain. it would be nice if anyone would share their experience and tell me how u got over it. because it may be a bit relief to know that i'm not alone.