GRRRR.
COULDN'T care less. Can't anybody write the English language any more?
“Could care less” is a New Yorkism. It means the same as “couldn’t care less.”
“Could care less” is stylish and zingy. “Couldn’t care less” is lumpen and earnest. Given that everyone knows what they both mean, one should always use the former.
Ignore the heathens. You’re absolutely right.
Ditto that.
I'm afraid there are increasingly fewer who can.
I’ll see your Grrrr and raise you a grumble.
I think “couldn’t care less”/”could care less” is like irony or sarcasm. It’s like “slim chance” is the same as “fat chance”.
Still, it is inaccurate. For that reason, I’ll suggest the more accurate “could not care less”.
“It’s accurate, and correct. I can’t believe this is being argued!” (We live in an age that sees correct grammar as an affront, and where it is ridiculed).