Please help with some jokes

There is a mental hospital where many mentally ill people live.

One day, the director there, in order to see how the patients were recovering, thought of a way and said to the patients: "You all come here," and he made a door on the wall. , and said: "Today, whoever opens this door can go home."

When the mentally ill patients heard this, they swarmed up and surrounded the painted door. The dean was very disappointed. He found that a patient was still sitting in the original position and didn't move. He thought it was okay, so he stepped forward and asked, "Why don't you open the door?"

He looked at it Dean, said something.

The patient secretly told the director: "I have the key here"