There is an old fable about a puppy that was vigorously chasing its tail. An old dog saw him and asked, "Why are you chasing your tail so?"

The puppy answered, "I have mastered philosophy. I have solved the problems of our universe, which no dog before me has solved correctly. I have learned that the st thing for a dog is contentment and happiness. I have further discovered that contentment lies within my tail. Therefore, I am chasing it; and when I catch it, I shall have happiness!"

The old dog just nodded his wrinkled head, then replied, "My son, I, too, have paid attention to the problems of our universe. In my own weak way, I have formed some opinions. Like you, I have judged that contentment and happiness are fine things for a dog and that, indeed, happiness lies within my tail. But I have also noticed that when I chase it, it keeps running from me; but when I simply go about my business, it follows after me."