“People to whom nothing has ever happened cannot understand the unimportance of events.”

Source: The Power of Now: A Guide to Spiritual Enlightenment

Source: Ship of Destiny

1949 - 1958, Speech to the Penguins' (1949)

Source: Theses on the Philosophy of History (1940), III
Context: Nothing that has ever happened should be regarded as lost for history. To be sure, only a redeemed mankind receives the fullness of its past — which is to say, only a redeemed mankind has its past become citable in all its moments. Each moment it has lived becomes a citation à l'ordre du jour — and that day is Judgement Day.

Source: Autobiography (1873), Ch. 1: Childhood and Early Education (p. 32 http://archive.org/stream/autobiographymil00milluoft#page/32/mode/2up/search/%22a+pupil+from+whom+nothing+is+ever+demanded+which+he+cannot+do+never+does+all+he+can%22)

As quoted in "The Gentle Philosopher" (2006) by John Little at the Will Durant Foundation https://web.archive.org/web/20130312115951/http://www.willdurant.com/home.html
Context: It is a mistake to think that the past is dead. Nothing that has ever happened is quite without influence at this moment. The present is merely the past rolled up and concentrated in this second of time. You, too, are your past; often your face is your autobiography; you are what you are because of what you have been; because of your heredity stretching back into forgotten generations; because of every element of environment that has affected you, every man or woman that has met you, every book that you have read, every experience that you have had; all these are accumulated in your memory, your body, your character, your soul. So with a city, a country, and a race; it is its past, and cannot be understood without it.

Letter to Mr. Fitzpatrick (30 July 1789) on the fall of the Bastille, printed in J. Russell (ed.), Memorials and Correspondence of Charles James Fox. Volume II (London: Richard Bentley, 1853), p. 361.
1780s

Source: The Age of Innocence