I could care less
A twisted, incorrect version of "I couldn't care less", invented by Americans (who else?) that clearly means the exact opposite of what is intended.
Idiots caught using it will offer up pitiful excuses such as "it's sarcasm, DUH!", or "it's historically acceptable, I'm not stupid, YOU'RE stupid!"
It is obvious to anyone who actually knows how to use sarcasm, or doesn't believe that stupidity is a recent invention, that these excuses represent nothing more than a transparent attempt to cover up the shame of talking like an idiot for most of their lives.
Stupid: "Pfft, I could care less about that".
I'mWithStupid: "You mean you *couldn't* care less. To say you could care less means you care at least a little. You're stupid, Stupid."
Stupid: "No, I was being sarcastic, *obviously*."
I'mWithStupid: "That doesn't even make sense."
Stupid: "Well, it's been used since the 1960s so it must be right!"
I'mWithStupid: "The fact that you still haven't corrected a mistake made by an idiot that long ago just makes you look *more* stupid."
Stupid: "...What were we talking about again?"
I'mWithStupid: "I couldn't care less..."