People say they don't care what others think about them all the time. I don't see how you can never care. I honestly do, in certain situations you have to.
I've learned that it's not what we want to do it's what we have to, which is not care. If you let people hold you down you'll never make it anywhere in life. You've gotta learn to NOT to care in a way. No one is flawless (reguardless of what ATRL thinks ) and you have to remember people are gonna always believe what they want to believe reguardless if the truth is right infront of them. It's nothing you can do about but fight it or move on.
I don't particularly care about what strangers think of me if I'm never going to see them again, but when meeting someone who is going to become a recurring person in my life (aka a new co-worker/student) then I start worrying and stress too much about all my actions around said person/people.
i used to a lot. but now i dont really care so much. like, ofcourse if someone says something ****ty to me i might get a little bit down, for like that one second i read it but in the end do i really care or take it seriously? um no lol.
) and you have to remember people are gonna always believe what they want to believe reguardless if the truth is right infront of them. It's nothing you can do about but fight it or move on. 
but in the end do i really care or take it seriously? um no lol.