I am sitting in a new cubicle this afternoon. I had been assigned to sit for the next few months in the cubicle assigned to another employee who was assigned to a team room for the next few months. She (the other employee) was indignant that I was sitting in her cubicle. I went to her manager and asked if she was really upset. I was told, "Yes, actually. It might help if you didn't leave your personal items (such as the backpack in which I transport the company's laptop that is assigned to me) on her desk. Also, don't eat at her desk. Maybe don't even use her wastebasket." (Ok, I made that last one up, but just barely.) Since I was told all that "might" help (I did not make that up), I decided to move my personal stuff and company assigned stuff to another cubicle that was heretofore unoccupied. My manager felt badly; so I made a joke about being a wandering Jew and explained that this really helps me because it proves that I don't need a mezuzah on my cubicle.
It's not her cubicle, not her computer, not her chair... but she feels a sense of ownership. Of course her feelings are misplaced; none the less, human beings do get nervous when their belongings are threatened. Chazal were sensitive to that fact of human nature, called in halacha "adam bahul al mamono"/a person gets panicky when their money/movable property is threatened. There is an extraordinarily long Biur Halacha that discusses this point in Hilchos Shabbos, siman 332, d.h. v'im hu sofeik. The starting point is that if a person's animal is sick and in danger of dying on Shabbos unless some blood is let (an old, well established cure, now largely abandoned), one is allowed to ask a goy to do that to his animal. For the Jew to do the blood letting himself would mean transgressing a Torah prohibition. While asking a non-Jew to perform the blood letting is usually forbidden by the Rabbinic decree of "amira l'akum", Chazal instituted an exception in this case. Why? "adam bahul al mamono" -- if he is not allowed to ask a goy to let the blood, the Jew will do it himself.
Seems simple enough -- relax a rabbinic decree to prevent a Torah transgression. The problem is, that Chazal didn't always do that. In fact, if a fire breaks out in one's house (a house that is separated far enough from other houses that the fire is not a threat to any neighbors), the person is only allowed to save enough food for the rest of Shabbos. Seriously: if fire is at night, three meals worth of food; in the morning, two meals; in the afternoon, one meal. Why? "adam bahul al mamono" -- if he is allowed to save whatever he wants, then as he is running around he'll see the fire spreading and come to put it out -- a very serious transgression of Shabbos. So in this case, Chazal added restrictions to forestall the panic.
When do Chazal relax decrees and when do they tighten them up to keep a person's panic from getting out of control? To really understand that, you'll need to learn that Biur Halacha. The basic rule, though, is that a restriction is relaxed except when that won't help. In the case of the animal, once the owner asks the non-Jew to take care of his animal, he will relax. In the case of the fire, he'll see that even more could be saved if he helped, so he'll rush in anyway.
There is another reason you should learn that Biur Halacha; to see the saintly genius known as variously as the Chafeitz Chaim and the Mishna Brura as a real human being. We sometimes forget that the Mishna Brura, the Chafeitz Chaim was also a Jew named Yisrael Meir Kagan, who was a husband and father. This Biur Halacha was largely the work of R' Kagan's son, who died very young. The Chafeitz Chaim (literally: He who desires life), ended this Biur Halacha with these words:
All the main points of these matters I copied from the manuscript of late son, who was great in Torah and extremely refined character, in honor or our teacher, our master, R' Avraham, May his memory and life in the world to come be a blessing, who died only because of the our many sins at the age of 23, 20 Kislev, 5652