I have two all-time favorite quotations. What are yours?

Not to slight Shakespeare or the King James Bible, both eminently quotable, nor all the world’s poetry; but my two favorites are these:

All the genuine, deep delight of life is in showing people the mud-pies you have made; and life is at its best when we confidingly recommend our mud-pies to each other’s sympathetic consideration.
—J.M. Thorburn, as quoted by Susanne K. Langer, Philosophy in a New Key (1941)

Philosophy is the disease for which it ought to be the cure.
—Feigl? Probably a misquote or variant of a quote, but this is the way I remember it.

Runner-up:

Humanity i love you because you
are perpetually putting the secret of
life in your pants and forgetting
it’s there and sitting down
on it
—e.e. cummings

Do you have some favorite lines that you come back to again and again like a touchstone?