When it comes to phrases and sayings, I’ve noticed that a good way to test their validity is to see if they also work in reverse.
“What doesn’t kill you only makes you stronger” – If something isn’t making you stronger, it’s killing you.
“If it looks stupid but it works, it’s not stupid” – If something looks smart on paper but doesn’t work in practice, it’s still stupid.
“Treat others as you would wish to be treated” – Don’t treat yourself worse than you would treat a stranger.
“Any job worth doing is worth doing well” – if something’s not worth doing, it’s not worth half-assing either.
“When there’s a will, there’s a way” – If you truly do not want to do something, it will be impossible no matter how easy it should be.