Why are people so attached to their possessions?
I think it's a primal need that is built in via natural selection. Those that had attachments to places and things outpased those who didn't. The affection a child shows for a favorite toy or a teenager shows for a favorite pair of shoes. Also, when a possession has been won over a great hardship, it has intrinsic meaning. This has a social and mental advantage when connecting to others. Social animals (like humans) must succeed in interactions to remain prosperous and leads to groupings of individuals for the overall benefits.