Could Not Care Less

It is fairly common to hear someone dismissively say that they could care less. Think about what has been said. If they could care less, than they do care. They may care a great deal for all we know, then it would be very easy to care less. 

Napoleon could not care less

Of course, we understand what they mean, but why not say "I couldn't care less." Or "I could not care less," which has a better rhythm to it, I think. In any case, there's no reason to say the exact opposite of what you mean by going with "could care less."