One of the General Populace's most common mistakes:

"I could care less"

Wait. The way that's used all the time--it doesn't make sense.
Think about it.
Don't you mean you couldn't care less?
Basically people are always saying, "Yeah, I care about that more than I should." Instead of "I don't care about that at all." Weird, huh.

"What's wrong? ... Nevermind, I could care less."
"Don't you mean you couldn't care less?"
"I could care less about your stupid grammar rules."
"I doubt it."