Hi, Daveiz. I can well understand your perplexion and your concern. Where the heart and the brain are concerned, both are mysteries. Often, in terms of gender and diagnosis, we occupy different worlds. Understanding and being understood are endemic when worlds intersect.   What you describe is both typical of the early stages of romance and bipolar. Often, when I try to describe to individuals what mild mania is like, I ask them to recall what it was like being madly in love.   Funny thing, though, when relationships begin to enter a new phase it's frightening how quickly emotions can change, though too often in our state of infatuation we fail to see it coming. Trust me, I'm speaking from a long track record of personal experience on this - and I'm sure this is fairly universal.   So, maybe she was in a state of mild mania and came back down to earth. Maybe her feelings for you changed when the relationship started to enter a new phase. Maybe she couldn't bring herself to tell you personally - and yes, fleeing on you like this is cowardly, whether bipolar or fallen out of love.   So, even though there is no answer to this, in your state of grief and bewilderment it is perfectly normal for you to keep wondering, to keep replaying things in your mind. Over time, your mind will settle down and allow you to let go. In the meantime, I'm sure everyone reading this identifies with your pain.