People become overconfident because they never bother to document their past track record of wrong predictions, and then they make things worse by falling victim to the dreaded confirmation bias - they only look for evidence that confirms their preconceived hypotheses

People become overconfident because they never bother to document their past track record of wrong predictions, and then they make things worse by falling victim to the dreaded confirmation bias - they only look for evidence that confirms their preconceived hypotheses

Richard H. Thaler, Misbehaving : The Making of Behavioural Economics