I like this line of thought. I’d add that another dodgy idea is stereotyping. You could make the mistake of saying customers are other-than-us; or you could think the customers-are-always-right. Nah. Just watch the TV programme Airline; some of the customers on that show are just as outrageous as the dodgy plumbers they like to nail on consumer TV shows.
Reflections on the power of rehearsal, from a master performer