I teach a couple of evening/daytime classes/workshops and I've had some individuals who have been difficult to deal with.
There was one chap at a writing workshop who I just couldn't fathom - I simply couldn't work out why he came back week after week as he made it clear with his body language and comments that he thought the entire enterprise was beneath him. Sometimes when I gave them an exercise on a handout I'd printed, all he did was take it between thumb and forefinger and casually toss it away as if he couldn't even be bothered to look at it. Every week (pretty much) given half a chance, he'd regale us with his epic poems, which were classically-inspred WH Auden pastiches and anti-Blair/Brown rants. I was accused of promoting a "soundbite culture" by asking people to give feedback.
I've got one now who is writing novels in English even though that's not his native language. He writes disturbing stuff too - horror/detetcive tales full of quite visceral, sexual violence towards women. And he is a keenie. I get to the classrom 45 minutes early - I'm a diligent tutor and like to have stuff set out, the kettle on and a plan on the board by the time people turn up - and HE IS ALREADY THERE. He lurks, either in the lobby on the public computer or in the classroom itself, and plagues me with endless questions.
Of course people are going to have questions when they start out, but some of his are of the "don't worry about that yet" kind, and I wish he'd raise them in the class rather than when I'm having my "get my head together" time - or, even worse, at the end of the class when I'm on a tight timetable for my bus home!
Sorry, bit of a rant - hope I'm not alone, anyway!