When society judges a person to be "useless", how should he deal with himself? In other words, who defines “useful”? If you think of "useful" and "useless" as two ends of a scale, you might as well take a look at the subtle dialogue they form at both ends of the scale.

The short-term "uselessness" (invalidity) of value investing prevents overcrowding and strategy arbitrage, and ensures the strategy's continued effectiveness (longevity) on a long-term scale. This is the perfect embodiment of "uselessness" in the modern financial field.