Trying to get my girlfriend back without much success

Call me crazy, but last week I embarked on this really big project to try and get my ex girlfriend to get back together with me. I know I probably shouldn’t, because she cheated on me with my brother…twice. But I can’t help thinking that she’s still the right woman for me. The problem, of course, with trying to get girlfriend back is that you really have to work hard to try and save a relationship that may not be worth saving in the first place. I mean really, how can you know for sure if she’s “the one” or just one of many?