Ohhhhhh mein gott, i can relate to that all too much. My brother suffers from a similar condition, let's call it "tends to stand in places that make you uncomfortable"-itis. While i will admit that much of my discomfort here is due to me being unnecessarily anxious, it still is fairly weird to stand up from your chair, place yourself directly beneath the ceiling light (located centrally in the not-too-big room and also closer to my chair than his chair) and face towards me and my monitor in order to operate a phone or tablet. I tell him that he could just as well do it while sitting, but he kind of just brushes that off. I've known that guy for literally all my life and he still manages to perplex me with some of his behaviours. >.> (i'm actually starting to wonder if he's hiding some unpleasant issues that he's reluctant to come forward with)
ANYWAYS, Tawa, i wish you luck in making them understand. It is really difficult to get people to lose annoying habits (especially when they don't think they're doing anything wrong), but one thing i've found that sometimes gets through my bro's skull is to demonstrate how annoying that habit actually is by means of replication. Of course, results may vary depending on the person, but making people conscious of their silly little habits is both great for making them think about it and an excellent way to troll people. :v