Some people are just kind of inconsiderate and it irks me. If you do a favor for someone, especially when you go out of your way during an inconvenient time, you should thank them before the favor (when the favor is accepted) and after the favor (when the favor is completed). If someone is going to go out of their way to help you, you could at least show some appreciation. That's all I ask for. A simple genuine thank you, before and after. It's not that hard.