A person who doesn't care would make a perfect politcian.
From others, little hurts, little hurts, little hurts then a big hurt and BAM, all done caring. Once that happens, they can't hurt me anymore. A light comes on and I see who they really are.
Edit: dealing with it... Two years ago, I met someone (not romantic) that I thought would be a Good Friend. However, I consciously approached it guardedly. One evening, during a conversation about relationships, she said something along the lines of she maintained contact with people she doesn't like just in case she needed something from them. It was just a quick comment. I have never forgotten it. I have helped her numerous times when nobody else would, expecting nothing in return. Once, I did ask her to help me but she said no. It was really just a test to see what she would do.
Now if I could just do that with everybody. Seems so cold, though.