After marrying a young filly, a ninety-year-old geezer told his
  doctor that they were expecting a baby.

  "Let me tell you a story," said the doctor.  "An absent-minded fellow
  went hunting, but instead of a gun, he picked up an umbrella.
  Suddenly a bear charged him.  Pointing his umbrella at the bear, he
  shot and killed it on the spot."

  "Impossible!" the geezer exclaimed.  "Somebody else must have shot that
  bear."

  "Exactly," replied the doctor.