Take Buffett's teacher Graham as an example. When he was a child, he experienced his family's transformation from rich to poor, and he had an inherent aversion to uncertainty. He was smart enough, professional enough, hardworking enough, and had accumulated rich experience at a young age. However, in the face of the Great Depression, the godfather of Wall Street still could not escape and was almost bankrupt. This was because the wave of small probability was so huge and so long that it was enough to sweep away all the dams built by wisdom and prudence.