I am a pack rat. I have trouble throwing away things that might be useful one day. Bottle caps, for instance. I think that it's an inherited trait. My paternal grandmother was a collector, too, of a magnitude that dwarfs mine. And my Uncle Howard's love of collecting reached psychotic heights, with hoards stored in alleys all over the cities where he lived.
I have collections stored in collections. Like these old baby wipe boxes that stack like legos. I haven't needed baby wipes in 17 years, but I've kept fasteners and buttons and wire in these containers all these years.