I would say it's about the regret of/mistakes haunting you. Always following you, effecting how you feel and how you make choices, and that her, herself is someone elses mistake, "just one of those ghosts". There first verse has, to me, a profound statement about how the singer feels safe but doesn't think it's right for her. Focusing you on the fact that things can be good but not what someone wants or doesn't like what it has made them. That she doesn't know who she is and is going to find herself by measuring herself by her mistakes. I do like the cry for the ability to identify the bitter from the broken hearted in the second verse. This implies that most of the singers mistakes are based on love, or perhaps lack there of, and just wants to know who she can relate with and trust. I also enjoy the sense of hopelessness, that it needs to be this way forever. That there is no way to stop it. I do like the last chorus as well, indicates that she can be many thing (read: grey) and that most people are black and white. I find that especially interesting because the singer previously forces people into that exact scenario of black and white by "broken hearts or twisted minds". It exemplifies the inability for people to rationalize themselves when they feel lost. Great song!