A man took his little boy to the zoo for the very first time.  Each time they would see a new animal the little boy would ask, "What's that?" And each time the father would explain.  When they came to a pen with a very large bird inside the father said, "And that, Timmy, is a Stork."

The boy stood there for a few moments and then began to wave and say, "Hi!  I'm Timmy!" After several times of repeating this he finally turned to his father and exclaimed, "Guess I'm all grown up, Dad, he doesn't recognize me."