I don't know if this qualifies as frugal or just crazy.
My mother (86) accumulated a collection of jars, cans and boxes of odd assorted nails, screws, nuts, bolts and other odd bits of hardware over the years. When her father (who was a carpenter) passed away, she "inherited" his similar collection.
The "odd bits" includes such things as old storm window mounting hardware, old doorknobs, cabinet knobs, rusty hinges, hooks with layers of old paint, mystery items ("I think this may have come off that old record-player you kids used to have"), 3-way electric outlet converters, fuses, carpet tacks, skeleton keys, other keys to unknown locks, padlocks with missing keys, skate keys (anyone remember those?), clasp that came off an old trunk, bent screwdriver with broken tip ("you might need that to pry up a paint can lid"), dried out rubber washers, assorted metal washers, rivets, grommits, shower curtain hooks, drapery hooks, broken drill bit, hammer head ("that's still good, it just needs a new handle")...and so on.
When she came to live with me, the whole mess, of course, came with her, and now sits in my cellar. She has resisted several attempts by me to get rid of it, so it continues to sit there. It seems to have some sentimental value for her, or something. I think I did manage to toss a gummy 50 year old roll of electrical tape, once.
Of course, occasionally something in one of the jars has come in handy, which just reinforces the "you never know when you might need one of these" attitude.
I gave up letting it bother me.