There is a broad combination of flaws, complexes and lack of self-respect that can easily be overpowered by "good emotions". Put the fear of dying alone and believing that this is "as good as it gets" and that you "can't get anything/anyone better" on top of that and there you have your recipe for getting back together. ._. All the popular musicians (especially women) are all about love or moving on, because those are topics everybody can relate to. But fact is that a lot of people are too weak to move on, including many of the said musicians. So they write songs about something they basically have no idea how to do, which is ironic.