How do you not care what people think about you?

I feel that way sometimes too, and it sucks, because for me, I really do care what others think of me. What you have to do is act like you don't care what they think of you, and after acting like that for so long, one day hopefully you won't care. Another thing that really helps me is writing in a journal. I know, it sounds a little geeky, but it really helps to get out all of my anger and frustration, and I actually feel better after writing everything down. You need to hold your head up high, and just forget about all of them. They don't know you, and everything you have been through so who are they to judge you? Really, who cares what they think about you...you just have to be positive, or just really try to be.