Give a man a fish, he eats for a day. Teach a man to fish, he eats for a lifetime. Give a man a fire, he's warm for a day. Set a man on fire, he's warm for the rest of his life.
Little Johnny's preschool class went on a field trip to the fire station. The firefighter giving the presentation held up a smoke detector and asked the class: "Does anyone know what this is?"
Little Johnny's hand shot up and the firefighter called on him.
Little Johnny replied: "That's how Mommy knows supper is ready!"