Young man goes to prison for the first time. At his first meal in the mess hall, another prisoner stands up, yells NINETEEN and everyone starts laughing. A few minutes later another prisoner stands up, yells TWO OH EIGHT and everyone laughs even louder. This goes on through the meal, with prisoners yelling out numbers and everyone laughing.
The young man returns to his cell and asks his elderly cellmate what the number yelling was all about. The old man tells him: "Jokes have been told so many times in here that we've assigned them numbers. Instead of having to tell the whole joke over again, we just yell out the assigned number.”
At the next meal the new prisoner decides to score some points so he jumps up and yells TWENTY-SIX. The mess hall is dead silent so the kid turns to the old man and asks what it means. The old man looks at him and says: "You didn't tell it right."