We downsized two years ago from a large 5 bedroom house to a much smaller four bedroom. In the end, it has proved a relief to shed possessions, things kept for the sake of it and without thought for the children who will one day be faced with having to clear our clutter!
It made us realise exactly what music we listened to and which books we had read and were remotely likely to read again. It also made us aware of how the digital world has changed our habits. We still have a hifi and a selection of cds but we listen to music now on ipods, Amazon Echo or computer. Similarly, many books are read on a Kindle and films watched on the computer.
I've also been one for keeping cards and keepsakes, souvenirs, boxes of photographs, cookery books, articles, favourite clothes now not worn and so on. I feel saved from the absurdity of it all now and glad to have had a massive clear out, I really don't miss anything. As has been suggested, you can always photograph things and take the process gently. I think the number of things we genuinely need to keep is, in reality, tiny and it's good to have reason to notice that.