There was a man in a mental hospital. All day he would put his ear to the wall and listen. The doctor would watch the guy do this day after day.
So, the doctor finally decided to see what this man was listening to, so he put his ear up to the wall and listened. He heard nothing. So he turned the mental patient and said, "I don't hear anything!"
The mental patient replied, "Yeah, I know. It's been like that for months!"