"Consider Steven Spielberg. At the age of thirty-six, he had become the most successful filmmaker in history. He's already responsible for four of the ten top-grossing films of all time, including E. T., The Extra-Terrestrial, the highest-grossing film ever. How did he reach that point at such a young age? It's a remarkable story. From the age of twelve or thirteen, Spielberg knew he wanted to be a movie director.

His life changed when he took a tour of Universal Studios one afternoon when...