six  mad men were taking to the psycartric hospital for cure and after three weeks the doctor had to see if they were improving he took a pen and draw a door close to the main door and ask them to go out.and the five of them were trying to make their way through the door the doctor drew and one was sitting down laughing at them and the doctor told the nurse this man sitting down is getting better.so,the doctor ask the man why did you not follow your fellows to pass through that door?and he said to the doctor laughing:because i have the key to that door you drew.