“We are forlorn like children, and experienced like old men, we are crude and sorrowful and superficial—I believe we are lost.”

Letter to Oskar Pollak (8 November 1903); cited from Briefe, 1902-1924 (1958) edited by [Max Brod]], p. 27<!-- New York: Schocken --> ; translation from Franz Kafka, Representative Man (1991) by Frederick R. Karl, p. 98 <!-- New York: Ticknor & Fields -->
Context: We are as forlorn as children lost in the woods. When you stand in front of me and look at me, what do you know of the griefs that are in me and what do I know of yours? And if I were to cast myself down before you and weep and tell you, what more would you know about me than you know about Hell when someone tells you it is hot and dreadful? For that reason alone we human beings ought to stand before one another as reverently, as reflectively, as lovingly, as we would before the entrance to Hell.

In a letter to Otto Juliusburger, September 29, 1942. Available in Einstein Archives 38-238
1940s
Variant: Do not grow old, no matter how long you live. Never cease to stand like curious children before the Great Mystery into which we were born.
Context: People like you and I, though mortal of course like everyone else, do not grow old no matter how long we live... [We] never cease to stand like curious children before the great mystery into which we were born.

Source: All Flesh is Grass (1965), Chapter 24 (p. 247)

The Comeback Kid (2015)

Palmira
8 1/2 Women

Source: Madame Bovary

1960s, I've Been to the Mountaintop (1968)

Source: The Angel Experiment

2000s, Kingdom of Fear: Loathsome Secrets of a Star-crossed Child in the Final Days of the American Century (2004)