At night, the lights in the cell block are turned off, and his cellmate goes over to the bars and yells, “Number twelve!” The whole cell block breaks out laughing. A few minutes later, somebody else in the cell block yells, “Number four!” “Well,” says the older prisoner, “we’ve all been in this here prison for so long, we all know the same jokes. This time the whole cell block rocks with the loudest laughter, prisoners rolling on the floor laughing hysterically.