Karl Popper on Truth

Here is a little philosophy I like from Karl Popper.  It is a little like saying "failure sucks but instructs," but far more elegant:

“Since we can never know anything for sure, it is simply not worth searching for certainty; but it is well worth searching for truth; and we do this chiefly by searching for mistakes, so that we can correct them”

P.S. The source is: Popper, K. R. 1992. In Search of a Better World: Lectures and Essays from Thirty Years.
London: Routledge.