It's back to that old adage of ones person's treasure is another's trash. What seems worthless, broken, worn-out, obsolete, unnecessary, excessive, cluttered, messy, or more to us is valuable to our clients - and perhaps the reverse is true also. While we might be able to go into someone's home and just start pitching things that seemed to have long outlived their usefulness or necessity in the lives of the people living there, we have no idea of what emotional attachment or sentiment there might be to certain items.
Something seemingly mundane and ordinary, like a rock, menu, ribbon, or the like that has no meaning or value to us we would toss in an instant. On the other hand, it may be highly prized as a memory by the person holding onto it. There is the chance that they don't remember why they have it any longer, but they still are unwilling to let it go because it must have meant something to them at sometime. This is part of what we encounter.
Souvenirs and memorabilia from sporting events, programs their children were in at school as they were growing, old report cards, awards from sports or youth organizations they participated in, items from their own school activities that they retained or that their parents kept for them, old family photographs (even the ones in very poor condition but cannot be replaced), hotel keys or menus from vacations, and so much more fill boxes, drawers, and other areas of our clients' homes. We have them also.
Books and magazines are great to have and often are used to read, share, or just add a nice touch to the decor. Most homes simply aren't large enough for any type of extensive library display, and electronic media (eBooks available for download or online reading) has replaced the need for physical copies of items for many people.
Some people collect more than others, and some people hang onto them longer than others (essentially never letting go of them), but we all have items, photos, or memories from the past that are important to us. When they become numerous and start encroaching on the living space in a home is when they become a more serious concern.
People start with their closets and fill them with boxes or stored items of papers and collected items, old clothes (in addition to items currently being worn), clothing that is never coming back in style (or if it did wouldn't look that good to wear) but is brand new or in excellent condition, and extra shoes or other accessories that were available at such a bargain price that several of them were purchased to have on hand (and never worn).
Once the closets are maxed out, dressers, armoires, cabinets, and other pieces of furniture (new, antique, used, and garage-sale finds) are obtained and pressed into service. Often they look very nice and fit into the decor where they are placed, but people are adding more to their living space rather than cutting back.
After the closets and furniture (or maybe in the reverse order for some people), the attic, garage, and basement (for those fortunate to have this extra living area) are used to store various items in boxes, bags, original packaging, in their as-is state, or other condition.
Once all of this available space is used, people turn to sheds in the backyard or offsite warehouse storage.
While it would seem to be a simple solution just to cut back on what people retains and to begin releasing some of this stuff rather than continuing to amass it and look for more and more ways to contain or store it, it just doesn't seem to work this way.
People could turn to a larger home, or they could begin culling some of what they own and retain. Neither seems to work that well for many people. While we know that people can navigate their homes better with less stuff being in their home competing for their living space - whether it is stored neatly away or just kind of accumulating in living areas - we also know that people are reluctant to even begin the sorting, tossing, donating, or removal process of their stored items.
In short, people hang onto their stuff because it has become a part of their life, it is easier to keep it than toss even a little of it (because that would mean making decisions on the relative value of something to them), and it would require a lot of time to begin removing any of it (significantly more time than it took to hang onto it initially).