One day a young man moved into a cave to study with a wise man. He hoped to learn everything there was to know. After giving his student a stack of books, the wise man sprinkled itching powder on his student's hand and left. Every morning the wise man returned to the cave to monitor his student's progress.  "Have you learned everything there is to know yet?" the wise man asked.

And every morning his student said, "No, I haven't." Then the wise man would sprinkle itching powder on the student's hand and leave. This was repeated for months. But one day, as the wise man entered the cave the student took the bag of itching powder and tossed it into the fire.

"Congratulations!" said the wise man. "You've graduated.  You've learned you don't have to know everything to do something positive. And you've learned how to take control over your life and stop the itching."