Go Mad Or Crazy

Ok so I was hanging out with a friend of mine and she starts talking about how the way people perceive you is the way you truly are. I can’t really remember most of the conversation but she made a point about how if a killer thinks they are a good person but everyone else thinks they are a bad person then they are a bad person so if someone thinks that they look pretty but everyone else thinks that they look ugly then they are ugly. At first I thought it was stupid because she didn’t make sense and plus she was smoking so I couldn’t really take anything she was saying seriously but it’s like 3 am rn and I can’t stop thinking about this. Does she have a point or is it lack of sleep that’s making me think this way?