Both RQS and I have clutter from other people that resides in our apartments. My clutter comes from artifacts of both my family, of my late wife and her family. RQS's clutter has similar sources, but more of them. And we have taken it upon ourselves to help each other clean up the messes which define our apartments.
In our generation, possessions were handed down from generation to generation. We expected our children to live in spaces bigger than the generations before them. My late wife preserved the engraved crystal her parents and grandparents used on special occasions. Others preserved expensive place settings used (if ever) for these occasions. And I don't intend to get started on tchotchkes such as Hummel figurines. The baby boomers as a whole seem to believe in accumulating "stuff" to be handed on to future generations - even if it has no demonstrated value or use.
Right now, I am trying to being my apartment into a shape where I can have friends over to visit. RQS is good for me in this area. And I know I'll have to pay her back this winter by helping her clear out the mess in her place. By the time we are done, I figure that we'll have an idea of what our long term relationship will look like. And that's a good thing....