The mental ward nurse entered a room and found a patient sitting in a chair pretending to drive a car. The nurse asked, "What are you doing, Charlie?" Charlie replied, "Driving to Chicago!" She wished him a good trip and left. The next day, she entered Charlie's room just as he stopped driving his imaginary car and asked, "How are you doing today, Charlie?" Charlie answered, "I just got to Chicago!" "Great," she replied. The nurse left Charlie's room and went across the hall into Bob's room, and found Bob sitting on his bed, masturbating furiously. Shocked, she cried, "Bob, what are you doing?" Bob said, "While Charlie's in Chicago, I'm doing his wife!"