Also, the notion of individual effort for individual property (and the sanctity thereof) cannot be taken for granted in the slightest. These attitudes change depending on the society you live in and how it functions.
People, in taking it for granted, seem to have the bizarre idea that this notion is absolute and overrides any social concern. "If I can work hard enough for X, why should I not have X?" begs the question of how you're getting X in the first place. News flash: It wasn't just your hard work. All that we have and earn is not only due to our own efforts and "luck" (and how is "luck" a fair determinant of who gets what?), but also due to the collective efforts of everyone else in society making that possible. Things that we know, do, and are capable of, are also due to our upbringing and the colossal infrastructure (physical and social and intellectual) of society that exists around us, supports us, and has done so since before we were born. This is as true for a billionaire as it is for the rest of us. People aren't entirely self-made and don't exist in isolation. Sure, you might "work hard enough" to afford a solid gold house, but who's building it? Who figured out how to build them in the first place? What social and political infrastructure exists that would allow you to do so? It's rather selfish and damn near sociopathic to assume that you have no obligation to give back to the society that made you and all your efforts possible in the first place. Some degree of individual freedom and property is something I think we can all agree is useful and productive in society, but the same goes for some degree of collective obligation.