Partly, I believe, this is genetic. I'm pretty well convinced that there's a gene for wanting to hang on to stuff, and I've got it. My grandfather hoarded building materials and my father hoarded food. I hoard information and information-bearing objects, which at least have the advantage of being relatively compact, compared to things like lumber and 5-gallon tubs of powdered lecithin.
This inclination is partly wanting to have a backup supply of stuff Just In Case You Ever Need It, and partly an aversion to throwing things out when they're Still Perfectly Good -- even though you personally may never use them. It's wasteful and wrong to send something useful to a landfill just because you don't need it, says my cultural programming, and I don't disagree. It's just that the extra work of disposing of it responsibly is often hard to muster.
In my case, I also hold on to things because they carry memory.
My memory is weird. I am great at remembering abstractions and patterns, and terrible at recalling anecdotal details. I think some of it is because my brain is full. I have a lot of book learning, and I know a lot of people, and I read a lot of things, and the more things you have jammed into your brain -- which really is adapted to remembering, what, probably a couple dozen tribe members and a few tens of square miles of savannah? -- the seek times start to get very long. I can remember most things eventually, but without a contextual trigger of some kind, it may not be until tomorrow. Or next week.
(At my little brother's graduation ceremony a couple years ago, I sat there looking at this guy sitting one section down and two over thinking He looks really familiar. I know him. Where do I know him from? for a good hour and a half before I finally realized: he's a checker at my local Target. I? Need. Context.)
So there's a lot of stuff that I keep around because when I look at it, it reminds me of particular times in my life. Clothes, for example. There are shirts that I never wear, that don't fit and are all raggedy, that I keep because they remind me of who I was back when I did wear them.
But I realized at some point that in many cases, I don't actually need the object itself. A picture will work just as well.
So this afternoon I've been photographing old shirts and putting them in a bag to donate / recycle. There are some I'm keeping anyway because I'm a sentimental git (TEP jerseys, concert tees, etc.) but I'm hopeful that I'll be able to make at least a small dent in the amount of matter we have to translate from X(apartment) to X(house). Because the apartment certainly is full of things, and I do not have a katamari.