A joke about a madman

The director of the mental hospital wants to see how many people have recovered. Ask the nurse to draw a door on the wall. I saw all the patients crashing into the wall crazily. The dean was disappointed. Suddenly he saw that only one patient was indifferent. The dean was very happy and ran to ask him, "don't you want to go out with them?" The patient replied, "these idiots, I have the key here!" "