I heard a story about a little puppy that noticed that whenever he was happy, his tail wagged, so the thought he had found the secret to happiness.
One day he shared the secret of happiness with an older dog. He said, “I have learned that the best thing for a dog is happiness, and that happiness is in my tail. So I am going to chase my tail; and when I catch it, I shall have happiness!”
The old dog replied, “I too, believe that happiness is a marvelous thing for a dog, and that happiness is in my tail. But I have noticed that when I chase it, my tail keeps running away from me; but when I go about my business, it follows me wherever I go.”
(From Sermon4Kids.com)