Yeah, I know, I'm learning Russian. It's my big obsession. And it's vous and tu in French, tous means "all" or "everyone", depending on the context. ;) The really interesting thing is that the two different forms are used differently in different countries and also change over time. I'd never even think of using "Sie" when talking to someone my age, but one of my teachers told me that twenty years ago it was still normal for students to say "Sie" to other students for months before they'd start using "du". Also, at least for people who care about manners (like I do), the situation has become a lot less clear, also because of the internet where everyone uses "du" all the time (except of course in professional e-mails etc.). Before it was very unambiguous which "you" you had to use with which people; today I often find myself in situations in which I feel that "Sie" is too formal and "du" too impolite.

On the other hand, there's more than this distinction to express politeness. There's also the use of first vs. last name, and other little details like that. Or things like imperatives: it's fairly normal in German, for example, to use imperatives all the time without sounding impolite ("Sit down" sounds like a perfectly nice invitation in German). In English that would sound like a command, and English often uses certain phrases to avoid imperatives (nobody would say something like "Would you like to sit down?" or "Why don't you sit down?" in German). I've heard more than once about Germans (but also people from other continental countries) being called very "direct" in English-speaking countries because of things like that. So, I really think that especially the English with their complex social codes have other ways of expressing what we express through these two forms of "you". Still, especially with Landa/Hellstrom I miss this difference because I see them saying "Sie" even after decades together, except in their most (emotionally, not physically) intimate moments.

Another rant. It's stronger than me.