What's the differece between "couldn't care less" and "couldn't care more"

I hear them used interchangably (maybe just a Baltimore thing?) but yeah, they use it as if it's the same thing. And it's confusing.

Also, when people say "Oh I'm so random!" OF COURSE you're random, you stupid fuck! EVERYTHING is random.

And when people say "I like cheese" out of the blue, and think it's funny. SO overused.

And when pPl TyPe LeIk DiS.