Little Johnny walked into the kitchen, saw his mother making a cake and
announced, "I'll be playing in my room for the next two hours. I sure
would
like a piece of cake when you're finished."

Later, when his mother brought him a piece of cooled cake, Little Johnny

exclaimed, "Golly, it worked!"
Puzzled, his mother asked, "What do you mean?"
Little Johnny replied, "Daddy said that in order to get a piece around
here, you have to be real nice and spend a couple of hours playing
first!"