E.g. the borders of countries:
They are formed by arbitrary "rules": Sometimes rivers and coasts, but mostly due wars and other weird, historical stuff that doesn't really exist in a reality outside of the ideological concept of our imagined self-importance (at least they seem so to me: Nothing in reality ever stops at a border from one country to another, let it be disease or just animals walking around or mountains going through or...). They do not have any basis in reality (contrair to concepts like "humid" and "arid"), they do not give any more value than a more-or-less-random guess, and still, people, all around the world, persist on using these "systems" to "measure" things (e.g. racism, xenophobia, but also "the [xyz-land] culture").
Why is that so? Why do humans create arbitrary systems with no basis in reality just to use these systems do to things with it that again have no better chance in succeeding than random chance (as you might have witnessed yourself if anyone talks about foreigners being stupid, lazy and so on or people belonging to the "race" x being ... and people belonging to the "race" y being totally different).
I really don't quite get that.