How can this phrase shut people up?

I think she gave that as an example, it doesn't work in all situations no, but the being ertive can. If he told you to shut up and quit it, you stand up, be as proud as you can be "I don't appreciate you telling me to shut up when I haven't done anything, I was just trying to get (insert neice's name) out of your way. You don't have to yell at me for no reason" Definitely turn it around on him and make him look foolish, after all you HAD been trying to help him out.