Conventional wisdom about the distant or quite recent past was seldom conventional wisdom at the time. The perceptive commentators (Trotsky and Churchill on Hitler, for instance, not to mention those who opposed the Iraq war before it began, those who initially said that British exams were being devalued, those who warned against university expansion, those who refused to accept that Gordon Brown was a competent Chancellor, I could go on) were in small minorities when it mattered, and only became recognised as wise when it was far too late. Mr O'Brien must have heard the story of the Emperor's New Clothes. Most people who hear this story think they would have realised the little boy was right. Experience tells me that most of them would have sided with the crowd, and believed the fake tailors. The curse of Cassandra was to be always right, and never believed.