Where does this saying come from?

[Bagsy]

"If it don't kill you, it just makes you stronger"

It was the title for a Bruce Willis album but have heard it quoted in various American Movies.

Any Ideas??

[Andy008]

The saying was made famous by the philosopher Friedrich Nietzsche.

It's actual truth is debatable, as the recently-retired-at-31-with-knee-injuries Jamie Redknapp will no doubt agree.

[Brugel]

Yes, it's from Nietzsche's book Twilight of the Idols and it goes: From the military school of life. - What does not kill me makes me stronger.