This question always pops into my head when I’m at the airport. Everyone working there is so miserable and unwilling to smile or offer help. Then I watch how rudely the staff is treated by tired or pushy travelers. I think it would be very difficult to stay positive and upbeat. I try and keep these poor souls in mind on those days when I have to deal with a less than pleasant person.  ”Oh well, at least I don’t work at the airport”.