@Determined, Dad has dementia, and I think he assumes it's all gone already. We took in some of his things to the aged care home, partially for his enjoyment, partially as memory joggers, and partially as things to tell a story about his life for the staff.
Mum is slightly hazy, but much more difficult to deal with. She frequently asks us or a friend to bring her something from the house, but a lot of the time things are not where she thinks they are. Even if they once were, so much has been moved around in the sorting out process that they're unlikely to be there now. She's got too much in her room, and it threatens to spill out onto walkways. We've taken in tubs to hold her craft bits and bobs, but her preferred storage method is plastic bags.
We removed two large bagfuls of plastic bags from her room when we brought the tubs in, and she wasn't happy about us taking them away.
We've lately been refusing to bring things in unless she gives us something that she's not using in exchange. Also makes her unhappy/angry. She got really cross with me when I insisted on sorting out a small stack of books, despite the fact that they were all stacked in a way that she couldn't see what they were.
And for that reason, we were never able to make much headway into sorting through things while they were still living at home.
It will be a relief when the house is sold, but there's a lot still to do before that happens.