This is an interesting topic. I hope it fills out...
Here's something from a couple of years ago that might be a bit off topic but really deserves a telling:
I arrived about 10 minutes late to an early first round to find my opponent had played 1.e4.
He was a kid (probably 11-12 years old) and I had no idea what his rating was.
Anyway, I had just spent a lot of time studying the Najdorf (about 2-3 weeks of intense study) but wasn't sure if I was willing to give it a go yet. Also, some younger players know a lot about fashionable openings and usually have an excellent memory but don't do as well in older or "boring" defenses.
So, I thought maybe I should play a Pirc or maybe I really ought to play solid via 1...e5.
Anyway, I sat there thinking about my first move for several minutes. The kid had started glancing up at me from time to time, but after these few minutes he was staring right at me as if to say "Oh my god, you don't know what to play against e4? "
Then he starts breathing fairly heavy (i.e. sighing as if to say "Whatever....just hurry up and move already.")
Well, since I thought it was bothering him, I decided to spend a couple more minutes (a la Lasker) just to see how much.
He keeps on sighing but stops staring at me, so I play 1...d6 and we get into it.
For the entire game, the kid was tapping his pencil, swallowing really loudly (what a strange habit), and of course, his perpetual sighing. Since I had the better position I tried to not let it really bother me but the people on the board next to us kept looking over at my opponent and either rolling their eyes or giving him a stern 'that's enough of that' look.
Kids today...
Anyway, to make a long story short, my opponent misplayed a combination and was down a piece for a pawn. I traded off the queens and rooks which left me with connected outside passers (that was fun) and absolutely no problems. But he played it out and kept banging, tapping, and sighing the whole time. Usually, when a game is over I ask my opponent if they want to go to the skittles room and have a postmordem, but I had no desire to spend any more time with this semi-rude little kid.
As I was waiting for the elevator this man comes up to me and asks me if I could say something about why his son had lost the game. Next to him is the aforementioned child and I'm not sure what to say. ("Is his dad going to berate me or something?")
So, I simply said that I thought he played too quickly in the early middlegame (we had about 2 hours for the entire game but the kid was still blitzing when he was obviously 'out of book'). Also, he started his kingside attack before developing all his pieces.
At this point the man turns to his kid and starts using sign language to translate what I just said.
Now it hits me... the kid is deaf.
He has no idea how loud he is!
He wasn't being a "pest" at all.
Needless to say, I was
very glad that I didn't complain about his noise during the game. That would have been an ugly little scene.