A drunk leaves a bar and decides to take a shortcut through a graveyard. It is raining heavily and very dark. The drunk fails to see an open grave and falls into it. He tries to climb out of it, but it is too deep and the rain has turned the dirt to mud and has made it too slippery to climb. He gives up after a while and decides to spend the night there.
A while later, another drunk leaves the same bar and decides to take the same shortcut through the graveyard. He, too, falls into that open grave and tries to climb out but the mud is too slippery. The first drunk is still sitting there and watches as the other drunk tries but fails to get out.
The first drunk stands up, taps the second drunk on the shoulder and tells him, "You'll never get out!"
He did.