“I could care less” is used because people don’t think about what they’re saying. They don’t mean it literally, they mean the opposite of the literal meaning – yet they’re not deliberately being ironic. Just lazy. It will never be correct.
Cisco – you’ve been hearing “it’s” meaning “it has” all your life, you just didn’t think about what words it was replacing. S’long; it’s been nice.
I acknowledged that 40 posts ago. I just had a brain fart. I use it all the time.
Which of The Whose albums is your favorite? 
I just went back and re-read my own post, and nowhere did I make any assumptions about why people do it – I just made some unflattering observations about how it makes them sound.
Hey, who’s been rummaging through my record collection?
Yeah, it makes them sound British, the dastards.
Brain farts have become a way of life for me. Everything I used to know is still in my brain, but I can’t seem to find it in a hurry. Sometimes, it’s sitting in plain sight like the Purloined Letter, and I keep trying to pry up the floorboards. Don’t really know where I’m going with this.
Speaking of Britishisms – “whinge” is one, right? Maybe I’m wrong, but I think it has a subtly different connotation than “whine”. At least, I think I’ve seen “whinge” used to mean “making a legitimate but tiresome complaint”, whereas “whine” suggests “making a complaint as a diversion to avoid acknowledging one’s one failing”. What do y’all think?
You did say they ‘insist’ on it, which suggests it’s a conscious decision to deviate from a norm, rather than a different and equally valid use of the language which happens to more closely reflect their speech.
This raises a pet peeve of mine. I have never corrected anyone who said “forums.” You are welcome to use it. Sometimes I even use it. But most of the time, I use “fora,” which is my personal selection of the two valid pluralizations of “forum.” I’m polite enough not to correct you when you choose the more modern (but perfectly acceptable) form, so why can’t you be polite enough not to correct me when I use the older (but still perfectly acceptable) form?
That must be a regionalism, then, Cisco. I hear the “correct” ( 
) form (“couldn’t care less”) far more often than the “lazy” form (“could care less”).
I haven’t heard “I couldn’t care less” in over thirty years. And I don’t think I’ve ever heard it in a TV program or movie. OTOH, I have heard “I could care less” on film as far back as the mid-60s.
I remember breaking the term down when I was a little kid and trying to rationalize “I could care less” and no matter what I thought - even “I could care less, but I don’t” - didn’t make as much sense as “I couldn’t care less.” Still, I’m always listening for quirky little things like that and I’ve never once heard the latter in real life. And I’ve lived and travelled all over. One variant I heard a lot as a teenager, because I had a friend who said it all the time, was the bogglingly nonsensical “I could give a lesser fuck.”
Steven Pinker gives the rationale for “I could care less” as sarcasm, with the tone adding an implied “As if I could care any less than I do now.”
I must admit it seems a weak explanation, although a plausible one. I just file it under idioms that aren’t literal, just as ‘bad’ doesn’t always mean ‘bad’. (Try deconstructing ‘badass’ literally. I dare you.)
Yeah, if actors are just actors no matter their chromosomal makeup, why have “Best Actor” and “Best Actress” categories at the Academy Awards? You wouldn’t even have to cut the number of awards in half – you could just have the “Big Four” performance plaudits recast as “Best Lead Actor in a Comedy”, “Best Lead Actor in a Drama”, “Best Supporting Actor in a Comedy”, and “Best Supporting Actor in a Drama”.
I tried to edit my previous post, but the clock ran out as I was searching for a relevant link.
Anyway, to contribute a spelling nitpick:
Well, if we’re being pedantic, we should type Fla-Vor-Aid (assuming that photo is an authentic depiction of the product).
I tend – perhaps incorrectly – to classify it as an Australianism, or New Zealandism… as in “whinging Pom”… so perhaps its is commonwealth usage.
“Whine” is higher pitched.
And Chef Troy may have my *spelt *and *whilst *when he prises them from my cold dead fingers. He may be living in McDonaldland, but some of us still speak proper ‘n’ all. 
I agree that it’d be a Commonwealth-ism rather than just a ‘British’ thing. As you say, it’s certainly firmly entrenched in Australian and New Zealand English.
Good description!
Saying that ‘whinge’ and ‘whine’ are the same thing is only as true as saying that ‘cobalt’ and ‘sky’ are the same thing - ie, both of the examples are shades of blue, but they’re not *interchangeable *shades of blue.
