(Pro 26:17 KJV) He that passeth by, and meddleth with strife belonging not to him, is like one that taketh a dog by the ears.
I would think that it is often obvious when we should stick our nose in someone else’s business. Or maybe the opposite is more appropriate. It is usually obvious when we should not offer our two cents worth. My wife tells the story of the time she was almost physically attacked in a store because she offered some advice to a father. I was not there. I know only what she tells me. She was, of course, completely innocent and his hostility was unwarranted. Maybe. Maybe not. It obviously was the wrong dog ears that she was ruffling.
So? I think the point is that we should lean toward not offering unsolicited advice. That is true even when it is obvious. There are times when people are being real fools, like pushing on a door that says “Pull”. Let them find out on their own. It will be embarrassing enough. It might also have more chance of being educational.