One night, a prison guard met with three inmates.
“You’ve been in here for years,” the guard said. “I’ll help you escape if you can pass one simple test. But if you fail the test, you’ll have five years added to your sentence.”
The prisoners readily agreed. In the dead of night, the guard collected them from their cells and took them to a diving board overlooking an empty swimming pool.
“Jump in!” the guard said.
The first prisoner jumped head-first into the pool and broke both arms.
Then the second prisoner jumped in and and broke both legs.
The third prisoner looked over the side and refused to jump.
“Congratulations! You’re a free man,” the guard said. “Just tell me why didn’t you jump.”
To which the third prisoner answered, “Well, sir, I can’t swim!”