Your first thought about a person isn’t usually your truest thought. It’s really what you would hear from other people about that person. Your second thought is your true conscience.
So say you say to yourself “that person is ugly…wait no they’re not ugly. … that’s an ugly thing to say!” The first part is what “society” thinks and the second is what you truly think. So don’t feel as bad if your first judgement is mean, because it’s the second thought.