Wikipedia

Get yourself into a hoarding support group. You don't have to be a total slob for these to be useful. And by far most hoarders don't look like the folks showcased on Bravo; reality shows specifically look for worst-cases that will have a psychotic break right on camera. Some of us really wish we'd fold our laundry rather than living out of the basket.

We all have a compulsion to collect stuff, whether Funko-POP bobble-heads, unplayed board games, multitools or in the case of Jay Leno, cars in different states of disrepair (and a lot of garages). It comes with being a mammal, and that is why rental storage is so tempting.

At hoarder support programs you will learn to organize your crap and work on large scale cleaning efforts. And you'll discover the emotional connections you have with all this...stuff.

And that is when you will develop an appreciation of what you actually need, what really sparks joy and what is a proxy for something else.

Also, if you're used to being poor, you might be in the habit of keeping stuff that can ve cannibalized for parts, to avoid spending money on new components. If you're in a municipal area, there might be an organization like a user's group with a junk library. Give your adapter collection to them.

Once you've gone through the agony of paring down you will appreciate the gaps between the possessions like the things themselves. Maybe more so.

And then, even when you can afford that new mini-laptop or a second, better propane grill, you'll actually ask yourself if you really need it. Maybe you know someone you can give the old one to. But eventually, you'll appreciate the phone / bike / can opener / wallet you got enough you don't have to get the new-fangled one.

So instead of having ten mechanical keyboards, you'll have a good one, a travel one and maybe a spare in case one breaks. Instead of having seven pocket knives, you'll have one with a solid selection and a separate screwdriver with twenty bits stashed away because none of the drivers on the pocket knives are very good. (Looking at you, Victorinox Cyber.)

It also means, before you buy that keen bauble, you're going to think about where it goes. (A bauble for me is a this space intentionally left blank indicator, like a coffee table that might otherwise draw bags of stuff from recent shopping.) If you see it going on a busy shelf or in a box, it saves you the trouble of buying it.

You will also be a snob over all your prized objects.