Who said, "That which does not kill me makes me stronger"? I'm seriously hoping it wasn't Jesus 'cause I've never yet disagreed with anything He's said.
This idea sounds grand when you aren't being challenged (likely I've said it a time or two myself), but come testing day, it frankly stinks. I won't be saying it anymore.
(BTW: I looked it up. It was Friedrich Nietzsche in Twilight of the Idols back in 1888. Remind me not to read it.)