[metmom]

How about saying *I could care less* when they mean they could NOT care less?

Saying that *I could care less* means that you are capable of caring less than you currently do.

Saying that you could not care less, means your sympathy meter is pegged on ZERO and it would not be possible to care less than you already don’t care.

[Navy Patriot]

You are language correct, however, idiom incorrect.

[NurdlyPeon]

I tell people that I could care less, but I'd have to be dead.

[JayGalt]

It’s clear you didn’t grow up in Brooklyn. There are regional idioms. So I could care less...

[Fledermaus]

I agree. But different around the country.

Like in the South we say, “bless his heart” as an insult.

[TalBlack]

If you e spent a certain amount of time in NYC especially many moons ago you’d have heard the originators of that phrase and understood it. It was a QUESTION, emphasis on the personal pronoun. Mainly Jews of Eastern European origin. I’ve often wondered how it got picked up by the rest of us as a statement (downward inflection) but for better or worse it has. Us kids in the 1960s said it all the time.

[fr_freak]

How about saying *I could care less* when they mean they could NOT care less?

I did some reading about this a while back, and apparently the original saying was "I could care less, but I don't see how." People just started dropping off the last part.