In a mental institution, a nurse walks into a room and sees a patient acting as if he's driving a car. The nurse asks him, "Charlie! What are you doing?"
Charlie replied, "Can't talk right now....I'm driving to Chicago!"
The nurse wishes him a good trip and leaves the room. The next day the nurse enters Charlie's room just as he stops driving his imaginary car and asks, "Well Charlie, how are you doing?"
Charlie says, "I'm exhausted, I just got into Chicago and I need some rest."
"That's great," replied the nurse, "I'm glad you had a safe trip." The nurse leaves Charlie's room, and goes across the hall into Fred's room, and finds Fred sitting on his bed masturbating vigorously. With suprise she asks, "Fred what are you doing!?"
To which Fred replies, "I'm screwing Charlie's wife. He's in Chicago!"