One that comes to mind for me: “Whatever doesn’t kill you makes you stronger” is not always true. Maybe even only half the time! Are there any phrases you tend to hear and shake your head at?
It’s true though. Saying this is not necessarily meant to be the end of a discussion.
Everyone knows that, though. So what’s the point of saying it when someone is trying to make things more fair?
Because saying things, even if they are known, is a thing humans do for various reasons. It seems that sometimes they need to be reminded simple truth.