I remember this quote vaguely from a junior high literature class, today I spotted it on a coffee mug of all places.
"Greatness is not in where we stand,
but in what direction we are moving.
We must set sail sometimes with the wind
and sometimes against it-but set sail we must,
and not drift, nor lie at anchor."
-Oliver Wendell Holmes
Incidentally (and totally coincidentally), I've had pets named Oliver and Wendell... it appears I have a name in place for the next one.