I've been getting rid of unnecessary stuff for years.  When I die, I don't want anyone going through my belongings and say "What the hell was he doing with this?"  That's what happened when my parents died.  People do have trouble getting rid of stuff, but I had no idea this was an American thing.  I'll tell you:  It's very uplifting and relieving to declutter.  I give most things to needy people or organizations.