kamen
Self-respect mostly (at least what’s left of it).
I’ve heard the right hand rule regarding magnetism and current direction (because it’s useful to illustrate correlation between vectors), but never about screws. Now that I think of it, it makes perfect sense there too, only that you have to imagine a thumb pointing down most of the time…
I can’t think of an equivalent phrase in Bulgarian for that, but it’s known that [most] threads tighten when turning clockwise… and if you don’t know what direction the clock goes, what are you even doing with screws or bolts…
And again there are special cases even outside of threads - for example in plumbing there are some valves that are open when the handle is parallel to the pipe and closed when the handle is perpendicular - and it might just happen that the closing motion happens counterclockwise.