I don't feel that that kind of detachment is necessarily a disorder. Many Eastern religions try and see surroundings as not being part of the self, and therefore, outside of your control. This is the way some people strive to live their lives, however, I don't think that people who hold this as a way to live their lives believe that grieving is wrong. I don't think that many cultures believe that there should be no grieving for the dead, but many do believe that there is no reason to be sad when objects break, get stolen, etc. Anyway, I'm kinda interested in that, so if anyone else has any feedback, I'd appreciate hearing it.