Gates argues that success can provide misleading lessons because positive results may encourage people to believe that their judgement is consistently reliable. When capable people experience repeated success, they may become less attentive to weaknesses, competitors or changing circumstances, and may assume that past performance protects them from future failure.

The quote presents success not as undesirable, but as something that needs to be interpreted carefully. Achievement can reinforce useful practices, yet it can also make it harder to recognise when conditions have changed or when earlier decisions benefited partly from timing, circumstance or luck. Gates therefore highlights the value of maintaining scepticism about one’s own position even during periods of strong performance. The idea can be applied to business leadership, personal decision-making and other competitive settings where confidence is useful but excessive certainty can reduce vigilance and adaptability.