I am learning a lot about myself through therapy and the thought that you came to the conclusion about your brother taking his future wife's last name was because you felt she didn't like you astounded me. That was a perception that I would have never came to myself without guidance from a therapist! It may not be easy to come to that conclusion but at least you realize why you do what you do. That can go a long way when trying to describe your actions to those you may have to apologize to later.