Little Johnny walked into the kitchen, saw his mother making a cake and announced, “I’m gonna go play in my room for a couple of hours. I sure would like a piece of cake after though!”
Later, when his mother brought him a piece of cake, Little Johnny exclaimed, “Wow! , 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 spend a couple of hours playing first!”
This joke is included in the Black Book of Jokes. You can order it from here.