"The sense that you're just bothering them is palpable, and that they know better than you."
Rings bells.
The latter is something I've experienced in the Castle.
I really didn't like being talked down to by someone who's probably been to only 2 airports in their life.
Made a mental note to avoid in the future.
I questioned myself afterwards to check if it was my attitude that was the problem.
No. Definitely theirs.