We still have LOTS of boxes in our basement from our move to our home. 4 years ago. 90% (or more) is WoBG's stuff that she just could not get ride of when we moved.
All of my spare bike parts (chains, cogs, tubes, bar tape, etc...) is in one box.
I have 2 boxes of personal stuff I had at work. I probably should get ride of most the stuff.
1 box of computer cables, and old router, an old scanner, etc... lots of old software. I should recycle the electronics.
1 box of cables, etc... for A/V and stereo equipment.
In several boxes, my old Apple 2E computer (soon to be 40 years old), the monitor, floppy drives, 2 printers, (dot matrix and electronic typewriter with a RS232 port), and all of the software.
One box of vintage camera equipment.
A few boxes of vacation, hiking, camping stuff.
Our last home had a walkout basement. Most it it was living space. our kitchen, dining room and family room. We had maybe 100 sqft of unfurnished basement that was FULL of stuff. (furnace, water heater, water softener, well pressure tank, water fliters, ,
I LOVE the basement we have now. ALL crap we store down there... And in case of storms, we have a place to hide.