Hindsight is blindsight. The very act of looking back on events once you know their outcome, or even try to imagine their outcome, makes it, by definition, impossible to view such events objectively.
— Mark Salter & Trevor H. Turner, Community Mental Health Care: A practical guide to outdoor psychiatry
Though you can still find subjects who don't know the outcome, ask them for their predictions, and compare those predictions with subjects who are told the outcome to find the size of the hindsight bias.
Another month has passed and here is a new rationality quotes thread. The usual rules are: