I got interested in electronics and computers in the early 70s & started building my own gadgets and eventually computers.
As of about 1980, someone asked if I could repair a computer - which turned out to be a core memory Minicomputer running a CNC Machine tool.
I've been designing and repairing industrial control systems and machine tools ever since, in addition to electronics etc. as a hobby.
That also means I've got an accumulation of parts stretching back most of that time, plus my own hobby electronics / audio / music / computer equipment collections.
I have a large detached bungalow (single storey house) with a large separate garage, and a good part of it is basically storage that happens to have a bed & kitchen included!
One of my friends called it a whole house man cave..
My "office" / desktop workspace has cupboards full of compartment cases and plastic boxes for small components and projects in progress, shelves full of folders and five (that I can see at present) PCs.
The dining room table hosts a 3D printer, one end of the living room has a large TV and surround sound system, the other end has by "music room" with multi channel recording system, keyboards, about a dozen guitars (repairing them is another hobby) and a drum kit..
The garage (about 20 x 20ft internal) has industrial racking on one wall, stacked with machine drives, cable reels and other large parts, and a workbench on another wall for woodworking & testing large electrical gear.
The house also has a loft/attic for storage and I added one in the garage.
(I'll leave out details of stuff "stored" where it was temporarily put down some time ago...)