If he's doing that sort of saving, you need to find out if he feels emotionally attached to the saved things, and/or to saving in general. It can be an honest to god mental imbalance, or it can just be weirdness, but if it's really a mental problem (Obsessive compulsive disorder with hoarding) then he needs professional help (ideally.)

Just throwing things out, if OCD, can send him into a legitimate panic, as much as locking a claustrophobe in a closet or covering an arachnophobe with spiders.

I wish I'd known this when I was cleaning up for my father. He had agreed to it, but he felt violated.