Why does time take the sharp edge from our griefs? The answer usually includes at least three factors--the subsistence of emotional reaction to it, its placing in the long-range perspective, and the press of new experience upon our attention. But there is a fourth factor whose existence is generally unnoticed and whose importance is equally unknown. This is the fact that the grief tends more and more to become a past memory, more and more recognized for what it really always was, that is, a thought.
-- Notebooks Category 21: Mentalism > Chapter 5: The Key To the Spiritual World > # 6