There was a 10-year-old boy who decided to study judo despite the fact that he had lost his left arm in a devastating car accident. The boy began lessons with an old Japanese judo master. The boy was doing well, so he couldn't understand why, after three months of training the master had taught him only one move.
"Master," the boy finally said, "Shouldn't I be learning more moves?"
"I realize that this is the only move you know, but this may be the only move you'll ever need to know," the master replied.
Not quite understanding, but believing in his teacher, the boy kept training.
Several months later, the master took the boy to his first tournament. Surprising himself, the boy easily won his first two matches. The third match proved to be more difficult, but after some time, his opponent became impatient and charged. The boy deftly used his one move to win the match. Still amazed by his success, the boy was now in the finals. This time, his opponent was bigger, stronger, and more experienced. For a while, the boy appeared to be overmatched. Concerned that the boy might get hurt, the referee called a time-out. He was about to stop the match when the master intervened.
"No," the master insisted, "Let him continue."
On the way home, the boy and master reviewed every move in each and every match. Then the boy summoned the courage to ask what was really on his mind.
"Master, how could I possibly have won that tournament with only one move?"
The master turned to the boy and answered, "You won for two reasons,". "First, you have been able to master the most difficult throw in all of judo. And second, the only known defense for that move that you have mastered, is for your opponent to grab your left arm."
The boy's biggest weakness had become his biggest strength.