RE:
What does it mean to be "None the worse for wear"?
I read the expression in a book and have a slight idea of what it means, but I would like to know for sure. I think it means you're okay, no lasting damage. Can anyone give me a more precise meaning, or is that it?

It’s usually used when a person –or object– has gone through some experience (adventure, use, accident) but is still in usable condition, or ok.

It means , “Oh sorry! My fault!” or “My Mistake”

You’ve gone through something not agreeable but you got through it with no damage. You know, what doesn’t kill ya, makes you stronger!