There was an old wise cat and a small kitten in an alleyway. The old cat saw the kitten chasing its tail and asked, “Why are you chasing your tail?”
To it the kitten replied, “I've been attending cat philosophy school and I have learned that the most important thing for a cat is happiness, and that happiness is located in my tail. Therefore, I am chasing it: and when I catch it, I shall have happiness forever.”
Laughing, the wise old cat replied, “My son, I wasn't lucky enough to go to cat philosophy school, but as I've gone through life, I too have realized that the most important thing for a cat is happiness, and indeed that it is located in my tail.  The difference I've found though is that whenever I chase after it, it keeps running away from me, but when I go about my business and live my life, it just seems to follow after me wherever I go.”

Wayne Dyer, Your Erroneous Zones, 1976