Imagine, while walking down the street, you see a sign on a building that says “Madhouse.” And for some reason you hear a man shouting at you from one of the windows saying: “HEY!! You’re crazy! You’re stupid! You look funny!”
Do you really believe him? Do you take it personally? Do you let it bother you? Of course not. You think: “Poor guy, he is locked in that madhouse and he thinks that I’m crazy.”
Well, you should have the same attitude towards difficult people, especially with strangers or people that you hardly know.
Why let someone, who clearly demonstrates by their disturbing behavior that they have personal problems, affect your attitude? The point is, you don’t. You’re walking free. They’re locked up. Don’t allow them to reverse that order.