Here it is:
A man is spending his first day in prison and is about to go to bed. Right before he falls asleep, he hears a shuffle and all of the Prisoners are awake and shuffling to the edge of their cell.
One man shouts “I’ll go first. 6821!” And everyone laughs.
Another man shouts “Me next! 1320!” And the prisoners are laughing hysterically.
The man, now confused, gets up and walks over to his cellmate.
“Hey man. Why is everyone shouting random numbers and why do people laugh after a number is called?”
His cellmate then responds with “We are telling jokes. We do it every night. There is a book of 9999 jokes that this prison has. Everyone has read the book and memorized it. Instead of retelling the entire joke over again, we just shout out the Joke number. It’s easier and we all know what each other are talking about.”
The man loved this idea. He was excited to get his hands on this book. The next morning, he strolled on down to the library and took out the book. He spent the entire day reading all 9999 jokes and picking out his favorites.
Night time rolled around and once the guards left, the prisoners all got up and walked to the edge of their cell.
The first prisoner shouted “8231” and was followed by laughs.
The next prisoner followed it up by shouting “3315” which was caused the prison to burst out into laughter.
The man was now feeling ready. He then shouted “4712”. The entire prison went silent.
The man was feeling upset and turned to his cellmate and asked “What’s wrong? I read the entire joke book, picked out a funny one and no one laughed. What did I do wrong?” The cellmate responded with:
“Some people just don’t know how to tell jokes.”