Marx said that he is not a Marxist but did Keynes say that he is not a…

No, John Maynard Keynes did not say anything equivalent to "I am not a Keynesian" or disavow the school of thought later named after him. Karl Marx's famous remark—"Ce qu'il y a de certain c'est que moi, je ne suis pas Marxiste" (translated as "What is certain is that I myself am not a Marxist")—is well-documented. He reportedly made it around 1882 in frustration with certain French followers (like Jules Guesde and Paul Lafargue) whom he accused of dogmatic "revolutionary phrase-mongering" a…