In the book “In 10½ Lessons from Experience”, Paul Marshall distills 35 years of investment experience, including more than 20 years at Marshall Wace, the global capital markets firm. He describes the gap between academic theory and market practice, focusing on the reality and persistent existence of ‘skill’ – the ability of the best professionals to outperform the market. He also emphasizes the frequency of uncertainty and human error, highlighting how a successful investment business must navigate by recognizing both the persistence of skill and the risks of cognitive bias, human error, and overconfidence.