Well, I don't teach but there have been/are some people in the classes that must be pretty exasperating to work with.
*One guy who's in my intermediate class is just a little strange. I can't tell exactly what's going on, but he acts normal and seems to actually be pretty funny, but when he gets on the mat, it's like he's confused, angry, frustrated, and has left his brain along with his shoes off the mat. Very odd, really
*The whole beginners class. My dojo is a friendly place (my instructors strive to make it a sort of family atmosphere), but these guys are just boards. They don't laugh, they don't talk ( some
talking is appropriate), and they're very stiff both in their movements and towards each other. I think it's really draining to my instructors.