"Whatever the number of hours that Maynard, no time was wasted. His mind worked quickly and he possessed to a high degree the power of concentration. He also worked steadily at home and was allowed to share his father’s study, a tribute to the son’s habitual quiet attention to the subject in hand, for the father was extremely sensitive to any kind of disturbance."
January 1, 1970
https://en.wikiquote.org/wiki/John_Maynard_Keynes