care- matter

And nothing else matters
Never cared for what they do
Never cared for what they know
But I know....

".....it doesn't matter how many times you fail. It doesn't matter how many times you almost get it right. No one is going to know or care about your failures, and either should you. All you have to do is learn from them and those around you because...All that matters in business is that you get it right once. Then everyone can tell you how lucky you are."
--Mark Cuban"

"Don't care" means you don't care about what happens. It won't change your views at all.
"Don't mind" means you are allowing it to happen.
"It doesn't matter" means you don't think it can help you, or won't affect the outcome.
"Nevermind" means forget about the fact I ever said anything.

http://forum.wordreference.com/threads/difference-between-dont-care-i-dont-mind-it-doesnt-matter-never-mind.134859/