My favorite song, I feel it closely relates a situation I just went through. She is insecure about herself or something from her past making the relationship complicated. For whatever reason, they broke up. I'm guessing he left her because he needed his space or needed to tke care of something. She felt abandoned and neglected (she thinks he gave up on her and that there are other girls or "phantoms"). He left and did his thing then comes back or tries to come back but she is now full of resentment and mistrust. She want's to be with him but is scared of being left again. So now she can't or doesn't want to tell him. He can tell just by looking at her that it's not the same as before and that now she seems to want "her" space. She tells him nothing and just leaves acting as if she never had cared at all and it doesn't affect her. Or else he left for two weeks, came back and she felt neglected and just blew him off.? Food for thought.