desks.
you find a seat, put your bag down, get your paper/pens out... and go to put the desk up.
but oh, how awkward, its attached to the next seat!!
you awkwardly grab at the often slippery desk, trying to make it obvious to the person sitting on the other side of you that, in fact, you're not trying to grope their ass, and manage to put it up.
THEN there's the issue of wrist damage, from them not being deep enough.
something i've discovered in engineering south - you can't even put your paper over the end of the table, because someone's head is there. not such a problem in napier [nor physics i don't think...] so you have your wrist at a funny angle, trying to write on your page, which is often filled with illegible scribbles. your wrist starts aching, but there's not much you can do about it.
then, just when you think all your desk dramas are over, the END of the lecture arrives. this is possibly the most awkward part, particularly in the physics building. the desk insists on swinging into your neighbour's leg, and there is absolutely NO way to escape it. many embarrassed 'sorry!'s later, you emerge into the sunlight to scurry off to your next location, or to be a uni bum.
in conclusion:
desks are out to get us; our wrists, our dignity, and our legs.