Another quirk: Here at a large Austrian university, my official German job title is "Universitätsassistent (postdoc)", which directly translates to "University Assistant (postdoc)". The official translation, however, is "Assistant Professor". And yet I don't have the rank of an Austrian Professor (neither "ordinary" nor "extraordinary"), and so German speakers would in fact be wrong to address me as "Professor so-and-so".
This is of course not only confusing to me. Since I also have a somewhat foreign name, students address me in all kinds of ways. I just got use to it as a fact of life.