The correct phrase is "couldn't care less", meaning that they don't care at all. "Could care less" is ambiguous and doesn't indicate what their current level of caring is (it might be very high), or whether they actually do care less, but only that there's a possibility of them caring less.
Sounds like you're an academic that received high marks in Stupidity 101. Try a class in the, "Basics of Ignorance I and II". I think you'll enjoy it.
Oh, and think about a course in, "Understanding the Obvious." It might benefit someone like you!