A $ for every time I:
* see the same passenger more than once & they ask "Are you always on this route?" Me: "yes mam, I specialize in Sydney to Canberra, but my colleagues fly all over south eastern Australia."
* a passenger asks, "how often do you work on international flights?" "no, sir, this is a regional airline, we do not fly internationally."
* when I pour someone a coffee (after clearly saying "would you like some coffee?"), and they look at me blankly and say, "oh, I wanted tea."
* and my personal favourite, "the check in staff said I could bring this into the cabin", referring to a bag a fraction smaller than a mini bus.