A Hollow Leg
Old Morty Mandelbaum went to the doctor complaining of a terrible pain in his leg.
“I am afraid it’s just old age,” replied the doctor, “there is nothing we can do about it.”
“That can’t be,” fumed old Morty, “You don’t know what you are doing.”
“How can you possibly know I am wrong?” countered the doctor.
“Well it’s quite obvious,” the old man replied, “my other leg is fine, and it’s the exact same age!”