The strange thing about growing old is that the intimate identification with the here and now is slowly lost; one feels transposed into infinity, more or less alone, no longer in hope or fear, only observing.

Letter to Queen Mother Elisabeth of Belgium (12 January 1953), Einstein Archive 32-405. Quoted in Albert Einstein: Creator and Rebel by Banesh Hoffman (1973), p. 261, and also partially quoted (with a reference to the exact date of the letter) in Einstein: His Life and Universe by Walter Isaacson (2007), p. 536