Being one that used to sit at the pointy end of the plane (small one) I can tell you the ATC guys (ground control) can get pretty testy when pilots don't listen to them. The ground control guys seem to be the worst. When you're a newbie pilot they don't have any patience and will chew you out when you ask them to repeat directions. When ATC takes over after you've cleared the airport they are quite a bit more relaxed. Obviusly so since there usually is quite a bit more distance between the aircraft. Taxiing, take off and landing are the most stressful for these guys. Take off you sometimes have only a 30 second window and do a rolling take off to get out of the way of a massive jet rolling in at 200 mph on your ass! It's a great hobby as well but much more expensive than this hobby.