Well I think this song is about a girl that really likes/loves a guy-whether he be a boyfriend or other-and things arent going right, and she keeps getting the blame, maybe blaming herself or hes blaming her. And when things sorta of hit rock bottom she asks herself "And why? all the possibilities" thinking they could have really had something. And she can't let go because she has let her feelings or heart win.
Seriously, no one cares.