why crying?

A wise man sat in the autdience and craked a joke.
Everybody laughs like crazy
After a moment, he cracked the same joke again,
This time less people laughed.
He cracked the same joke again and again
When there is no laughter in the crowd.
HE SMILED AND SAID
you can't laugh at the same joke again and agian.
but why do you keep crying over the same thing over and over again.?