I think it’s trauma based.
I have the same problem. I’m trying to get rid of Christmas ornaments. A lot of them were my mother’s. When I look at them, I think of us buying them together. My mother was severely mentally ill, and a hoarder. But she loved Christmas and always tried to do something to make it special.
When I see the ornaments, all the bad memories go away and I feel like I’m close to my mother. I’m touching something she touched. I can’t put a price on that. I guess they represent the mother and childhood I wish I had instead of the one I did have.
Another issue is I became very clutter blind from living in very small single apartments with little storage. It was impossible to keep some of these places orderly looking because there was just insufficient storage. One place had no closet at all or anyplace to put a cabinet or dresser. Another had one small closet for the entire apartment. And I was not allowed to get rid of things that weren’t mine. So being poor and being in an overstuffed space can make a person clutterblind and make it even more difficult to realize when you have too much, when everything is in a closed box and you can’t see what it is.
I also can’t figure out how many is the normal amount. Of anything. I just have no frame of reference. Some people have posted on here about the normal amount of clothes and other items and that’s very helpful. It turns out I don’t have nearly enough clothes. But too much household goods.
About your original question, I do lose the memory if I don’t see or touch something. The memory comes back when I see it. I’m very forgetful, I’ve blanked out big parts of my childhood that were bad, which is most of it. I’m hoarding good memories because I don’t have very many.