Laughing until you laugh no more
A wise man once sat in the audience and cracked a joke.
Everone in the audience laughed uproariously. After a moment he cracked the same joke again and a little less people laughed this time.
He cracked the same joke again and again, when there was no laughter in the crowd, he smiled and said:
"When you can't laugh on the same joke again and again, then why do you keep crying over the same thing over and over again?”