The Secret of Long Life

There was an old man about 85 years old in very robust health. Newspaper and television journalists came on his birthday to interview him about the secret of long life. So he said, "Oh, no problem, I just walk about five miles every day, and then I do some bicycling and swimming whenever I like. But walking is a basic routine in my life; I make it a point to walk five miles a day, every morning." But one of the journalist was very skeptical, said, "My father also walked five miles every day but he died at fifty." So the old man said, "Now then, he didn't do it long enough, that's why."