John The Jogger.
John goes to see his doctor. He says, "I'm feeling very much under par, doctor. My joints are stiff, and it's an effort to climb the stairs." After an examination, the doctor says, "You need more exercise. Try jogging for about three miles a day. Give me a ring after about a week, and let me know how you're getting on." A week later, the doctor gets a call from John. "Hello, John," says the doctor. "How are you getting on with the jogging?" John is panting, and he says, "I'm fine, doctor, but I'm 21 miles from home. What do I do now?"