In a psychiatrist’s waiting room two patients are having a conversation. One says to the other, “Why are you here?”
The second answers, “I’m Alexander The Great, so the doctor told me to come here. “
The first is curious and asks, “How do you know that you’re Alexander The Great?”
The second responds, “God told me I was. “
At this point, a patient on the other side of the room shouts, “No I Did Not!”
This joke is included in the Black Book of Jokes. You can order it from here.