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)."