I think what she meant was, if you want to change a person you can't and you need to move on. It is like trying to change your husband, it ain't going to happen.
I would be amiss to think I don't have faults but also I think that alot of people treat us badly and it is not from our own faults but from theirs. Surely you have met people who are toxic and you just prefer not to deal with them.