"And I think very, very often of that excellent painter Monticelli, who people said was such a drinker and insane, when I see myself coming back from the mental labour of balancing the six essential colours, red — blue — yellow — orange — lilac — green.
  "Work and dry calculation, in which one’s mind is extremely stretched, like an actor on the stage in a difficult role — where you have to think of a thousand things at the same time in a single half hour."