I don't count old toys & clothes (Clothkits) that GC use or significant memorabilia. I don't mind storing stuff they will use but don't want to be a rubbish bin. Son always reluctant to sort his stuff so I took small amounts regularly to his bachelor flat & distributed it - he probably never noticed. He is married now & lives abroad when he came over by car, I had the final bags ready to go. He looked through, said "Don't you want to keep these? ,in offended tone (I'd already sorted a few for me). He did sort them but then I couldn't throw some discarded things away. With my late daughter's things, I have a rule - if it triggers tears or other memory, I keep, if not discard. Over the years attachments lessen except for really important things. We also had late parents' stuff, some integrated, some bits still to sort, many bags have been recycled, chucked etc and we always seem to be doing this. Does what's left reproduce??
If we downsize we'll be dratic, if not boot will be on other foot for kids. DS is an ace chucker, driven by his wife, which means he has no room for extras - 3 storey house plus basement & garage. I love him dearly, especially when he says our house is too full if stuff. Of course there's all my old files & books but that doesn't count as I might write my book one day...