How about this one from Gary Hamel’s Leading the Revolution;

"Dakota tribal wisdom says that when you discover you’re on a dead horse, the best strategy is to dismount.  Of course, there are other strategies.  You can change riders.  You can get a committee to study the dead horse.  You can benchmark how other companies ride dead horses.  You can declare that it’s cheaper to feed a dead horse.  You can harness several dead horses together.  But after you’ve tried all these things, you’re still going to have to dismount (p. 55)."

Quotebook: Change