The problem with cleaning is that there are just so many categories of stuff.
Volume is not a problem. Volume can easily be handled by Storage. You have this much stuff, you find that much plus a bit of space, and then you insert Stuff A into Space B. Voila! And since the universe is, theoretically, infinite while the amount of stuff in it is, according to the scientists, insufficient to keep it all from flying off into heat death, so much so that they have to invent whole categories of stuff just to keep the equations from collapsing, then finding that bit of space for your stuff should be no problem.
Of course the people who worked that out didn't have kids, optimizers or packrats sharing their living quarters, so it's probably not that easy. But still - stuff; space; solution. Easy.
No, the problem is that it's not just stuff. It's many kinds of stuff. Or, rather, it's many different subtle variations of a few basic kinds of stuff and you have to figure out a) how to categorize it in such a way as to make keeping it useful (i.e. so you can find it again someday), and b) what to do with all those variations once you have satisfied the requirements of point a. Because categorization implies organization and organization is a bear.
I have in my office the paper trails from at least four different courses that I've taught in the last calendar year, all of which had to be organized internally and then put into some kind of macro-arrangement where I could access them again. So far I've gotten past the first hurdle but not the second.
The second hurdle involves more lifting, moving and refiling.
I have two short filing cabinets in my office that are currently filled with other stuff that should probably be moved out of the way to accommodate all the class stuff that I actually use. This is not going to be pretty, as it will no doubt involve moving boxes up from the basement in order to load them into the filing cabinets so I can keep all the course stuff together and then loading all of the other stuff into those now empty boxes and taking the once-again full boxes back downstairs. So there will be temporary local increases in entropy, is what I'm saying.
On the other hand, I have now reduced the stuff volume in my office to the point where I am reasonably confident that I could get from one end of the room to the other without serious injury in the event of a natural disaster.
And that's progress.