From an astonishing book called The Healing Code:
"When I was about ten years old we had a special assembly one day in school. Unlike some of the other assemblies we had, it was mesmerizing, inspirational, and fabulous. A karate master shared secrets of life while he did all sorts of amazing feats like breaking boards, bricks, stones, huge chunks of ice, and fighting off many attackers at the same time.
He told us a true story that has stayed with me ever since. It was of a young boy in China about my age who was in the initial stages of learning a certain form of martial arts. The school he attended would periodically have an event for the families and friends of the students to celebrate their progress. Different students prepared far in advance to do their particular demonstration. The master told this one young boy that at the event he was to break a certain number of a certain type of brick. This task was a little bit unusual since the boy had never done it before and would not actually perform the action beforehand! Yes, he would practice like everyone else, but would only practice the technique, not the actual breaking.
When the young boy expressed concern to the master, the master simply smiled and said, “You will have no problem. You know everything you need to break the bricks.” The day of the event came and all the students performed brilliantly to the audience’s delight and appreciation. Finally, for the finale, the young boy came out, bowed to the crowd, bowed to his master, and attacked the bricks as he had practiced. To everyone’s amazement, the bricks broke easily under the boy’s hand.
The master stepped forward, motioned for everyone to be silent, and explained that what the young boy had just done had never been done before in history. Not by himself, not by any of the great masters of the world. The master shared that the boy, while talented, had been able to accomplish this seemingly impossible feat not because of talent, but simply because he believed he could perform the feat with no doubts in his heart. The breaking of the bricks was simply the physical manifestation of the boy’s internal beliefs."