I saw where the mayor of Parker, Colorado was talking about the current economic situation, and he repeated the oft-stated maxim that "What doesn't kill you, only makes you stronger." The veracity of that idea is in doubt, as it could be that what doesn't kill you, only makes you so miserable that you wished that it did. Or perhaps it is only half the story. For example, one could finish the statement thusly:
"What doesn't kill you, only makes you stronger. But that which does kill you, well . . . kills you."