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?
In the same vein (and at least as dangerous): “Pain is just weakness leaving the body.” No, you testosterone poisoned numb-nuts - it is your body’s way of telling you that something is not right. Stop and listen!
With the exception when someone starts out a new sport or even manual work, like yep you’re a bit achy now, good on you because that’s the feeling of laziness escaping!