‘Mouth Breather’
Like yeah I don’t get this one. We all breathe through our mouths (and noses), because we have to. Yet I read this sometimes as it is used like an insult. So what are you saying? You’re insulting someone for doing what billions of other human beings have to do naturally?
“Bless your heart.”
Means they think you’re naive.
Then of course all the sarcastic ones like “Smooth move, Ex-lax,” “Way to go, Einstein,” and “No shit, Sherlock.”