From Within a Budding Grove (1924), by Marcel Proust.

“Some one advised me once,” I began, thinking of the conversation we had had with Legrandin at Combray, as to which I was glad of an opportunity of learning Elstir’s views,–not to visit Brittany, because it would not be wholesome for a mind with a natural tendency to dream. “Not at all” he replied. “When the mind has a tendency to dream, it is a mistake to keep dreams away from it, to ration its dreams. So long as you distract your mind from its dreams, it will not know them for what they are; you will always be being taken in by the appearance of things, because you will not have grasped their true nature. If a little dreaming is dangerous, the cure for it is not to dream less but to dream more, to dream all the time. One must have a thorough understanding of one’s dreams if one is not to be troubled by them; there is a way of separating one’s dreams from one’s life which so often produces good results that I ask myself whether one ought not, at all costs, to try it, simply as a preventive, just as certain surgeons make out that we ought, to avoid the risk of appendicitis later on, to have all our appendices taken out when we are children.”