I worked on a help desk, both as a worker and supervisor, for 14 years. During that time, I noticed one of the hardest parts about working--whether on a help desk or otherwise--is swallowing your pride.
When you drill down to the basic level, human beings don't like to be ordered around. It is demoralizing. It feels bad. It's the reason some servers look annoyed when someone asks for more napkins or a refill on a drink. It's also the reason your help desk worker is irritable when you run into his cubicle and yell at him that you need help.
Granted, some people are much better at customer service than others. Do they lack that pride mechanism that is so ingrained in many of us? Or are they simply better at hiding it? One of the best employees I ever had was a people pleaser. People came directly to him with computer problems and, instead of telling them to put in a ticket (as was the policy), he'd jump up and happily rush to help them. He didn't appear to be hiding any irritation, at all. He was genuinely a pleasant person who liked to help people, even if they were ordering them around.
On the flip side, I once worked with a woman who was so bitterly disgusted by being given orders, she pushed it back on the person issuing the order. She was a master at it. If someone told her they needed something, she'd immediately bark back that they needed to put in a ticket. Or she'd push it off on another team in a voice that made clear that the other team was beneath her and therefore had to do her grunt work. Even if it meant only offloading a small part of this task to the other team, she'd do it. I even saw her treat management as though they were supposed to do the work she was above. I think everyone was too scared of her to put her in her place.
Pride. It's a dangerous thing in the workplace. How do you swallow your pride and realize you're in a job to serve others? Do you find that being ordered around is difficult to take, even when a paycheck is tied to it?