I am in possession of about a dozen brand new oil filters of various types and sizes. I know that many of them do not fit anything I currently own. I know that if I did own one of the vehicles again that they fit, I would probably not remember that I had one already. They serve no practical purpose other than to adorn a shelf in the garage. I cannot throw them out, as they are new and perfectly functional. I console myself with thoughts like....one day, I am going to look them all up and put them on eBay. I am not trying to hoard them all, it is just the inertia.
I am in possession of about a dozen coils. Most of them are black Bosch coils with labels long gone. Some of them have a piece of masking tape on them with words like BAD, and SUSPECT. I don't really trust the conclusion I reached whenever it was that I pulled these coils, so I can't throw them out yet. Others have vehicle names on them that I no longer own. You never know, I might stumble across another 6V Ghia with a suspect coil anyday. Then I would look brilliant. And regular readers will know that it would not be unusual for a former vehicle to be owned again (Repeat Offenders, Recidivism)
I am in possession of many dozen door mirrors. Many of them are broken or blemished in some way. A grub screw stripped, or a pivot mechanism shot so that the glass just flops around, seriously pitted chrome, etc. some of them were horrible "upgrades" by previous owners of vehicles I no longer own. Some of them fit vehicles that I currently own. Spares that I would never use because of their condition. I can't throw them out because they may be useful on a track car or a project, or as spare glass.
I am in possession of more than a dozen motorcycle windshields. None of them fit anything I currently own. In fact two of them fit vehicles that I have never owned! They are mostly in good shape, so I can't throw them out. You never know when a hot rod Cafe project will need a cut down windshield from a BMW K12RS. They are bulky and difficult to store without scratching. Eventually, in about 30 years, there will be more than a dozen very scratched motorcycle windshields. Perhaps then the kids or grand kids will discard them.
I am in possession of several sets of used spark plug wires. They were all removed from vehicles to eliminate them as potential contributors to some malady. Since I also replaced points, condensers, and coils (see above), they could all be perfectly fine. Or not. Best not to throw them out then.
I am in possession of 2 BMW /2 bench seats which are shedding fine horsehair, a sheet metal replacement for the bottom front of a 356C, a multi-tool for a Norton, a pitted rear script from a Mercedes 230SL, a 1.7 914 motor, cracked turn signal lenses for a 69 Karmann Ghia, several not-so-good sets of /5 mufflers, rear door panels for a BMW 3.0CS, a dented CB750 tank, a tail section for an R100RS, a spare wheel for a Puma GTC, a broken speedometer for a 1966 VW Bus, multiple sets of airhead luggage, a deformed spoiler from a Mercedes 2.3 16V, a 914 rear decklid, etc, etc, etc.
This could go on for pages and pages. Items are in the garage, the basement, the attic, other undisclosed locations. I firmly believe that we gearheads are very different from the hoarders seen on reality TV shows. We are more like inventory builders. Then again, perhaps we just have different areas of specialization, or perhaps we are even sicker because we actually attempt to justify what we hoard....