The story of the Fisher King begins when the king is a boy, having to spend the night alone in the forest to prove his courage so he can become king. And while he's spending the night alone he is visited by a sacred vision. Out of the fire appears the Holy Grail, the symbol of God's divine grace. And a voice said to the boy, "You shall be keeper of the grail so that it may heal the hearts of men." But the boy was blinded by greater visions of a life of power, glory, and beauty. And in this state of radical amazement he felt for a brief moment, not like a boy, but invincible, like God. So he reached in the fire to take the grail and the grail vanished, leaving him with his hand in the fire to be terribly wounded.
Now as this boy grew older his wound grew deeper, until one day life for him lost its reason. He had no faith in any man, not even himself. He couldn't love, or feel love. He was sick with experience; he began to die. One day a fool wandered into the castle and found the king alone. Now being a fool he was simple-minded; he didn't see a king, he only saw a man alone and in pain. And he asked the king, "What ails you, friend?" The king replied, "I'm thirsty. I need some water to cool my throat." So the fool took a cup from beside his bed, filled it with water, and handed it to the king.
As the king began to drink, he realized his wound was healed. He looked in his hands and there was the Holy Grail, that which he had sought all of his life. He turned to the fool and said with amazement, "How could you find that which my brightest and bravest could not?" The fool replied, "I don't know. I only knew that you were thirsty."
~ The Fisher King by Richard Gravenese