The doctor takes the three patients to the top of a diving board looking over an empty swimming pool, and asks the first patient to jump.
The first patient jumps head first into the pool and breaks both arms.
Then the second patient jumps and breaks both legs.
The third patient looks over the side and refuses to jump. "Congratulations! You're a free man. Just tell me why didn't you jump?" asked the doctor.
To which the third patient answered, "Well Doc, I can't swim!"