Doctor: “I see you’re over a month late for your appointment. Don’t you know that nervous disorders require prompt and regular attention? What’s your excuse?”
Patient: “I was just following your orders, Doc. “
Doctor: “Following my orders? What are you talking about? I gave you no such order. “
Patient: “You told me to avoid people who irritate me. “
This joke is included in the Black Book of Jokes. You can order it from here.