Jan Tinbergen describes Keynes' confidence. "In 1946 I had the privilege to meet personally John Maynard Keynes. I informed him that I had estimated the price elasticity of the demand for export goods of a number of countries and found figures around -2, the figure he had used intuitively in his famous 'The Economic Consequences of the Peace' (1920). I thought he would be happy that his intuition had been 'proved to be correct'; typically an econometrician's attitude. His reaction was different: 'how pleasant for you to have found the correct figure.' For him his intuition was the truth, rather than results of econometrics. He may have been right! This may have been a lesson for me."
bc searches for the subject's reference; half in jest Einstein quote.