>>101606605I think saying "I couldn't care less" implies you care more.
If you say "Eh, I could care less," it's a very neutral feeling, it's the essence of not caring. No positive, no negative.
But if you're saying "I couldn't care less," it's more direct and angry. If someone says "THERE IS NOTHING I CARE ABOUT LESS THAN THIS, I COULD NOT CARE LESS ABOUT THIS." it kind of implies you do care, right?