I don't mind if my yard leads into a forest. That's great. But I do want to know where my yard ends and the neighbors' yards begin. I want lines drawn, nice and clear lines that clarify my responsibility. Admittedly, I also want others to know… "Hey, I'm not responsible for whatever you see over there!"
The same is true at work. I like my desk to be… mine. I like my desk clean, my filing cabinets organized, and my books shelves by topic and then alphabetical. Don't enter my space without asking, and definitely don't return books to be helpful — other people never seem to place them back in order!
Controlling my space, and wanting it as perfect as possible, is more than preference. It borders on a need — a desire to have a little bit of order and control, when we know control is so limited in life. My spaces are at least something I maintain, along with my equally picky (and sometimes pickier) wife.
I don't like that our house isn't done, that boxes and filing cabinets aren't organized, that we need to organize many things and never have the time to complete these tasks, but at least we are in charge of our spaces.