Santa, Banta and one of their friends are patients in a mental institution and are preparing for an examination given by the head psychiatrist. If they pass the exam, they will be free to leave the hospital. However, if they fail, the institution will detain them for five years.
The doctor takes them 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 Banta jumps and breaks both legs.
Santa 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 Santa answered, "Well Doc, I can`t swim!"