If past history was all that is needed to play the game of money, the richest people would be librarians.

The line is a pointed reminder that investing is not a mechanical exercise in reading and replaying the past. Even exhaustive knowledge of historical prices, balance sheets, and market cycles cannot by itself produce superior returns, because markets change, competition evolves, and future outcomes hinge on judgment under uncertainty. The quip also critiques overreliance on backtests and “data mining”: information is abundant, but insight is scarce. In Buffett’s value-investing worldview, success depends less on possessing more historical facts than on interpreting them—understanding business quality, incentives, and long-term economics—and having the temperament to act rationally when others do not.