I was in almost constant contact with the public throughout that time. The customers ran the gamut from saintly to "if I could get away with it I would kill this guy." The level of rudeness by some of the customers during that time was stunning. I have never seen humans treating others so horribly.
Nevertheless, I always treated customers the way I would like to be treated. It's something I inherited from my dad. I never saw him be even remotely rude to a service person. Ever.
So now, I go out of my way to be nice to people serving me. The only times I have lost it were when the person was being rude or snotty and I was in the right. Even then, I have invariably apologized.
I find working in the service industry to be a study in social psychology, maybe even abnormal psychology *LOL*
Ah, that's the true test, isn't it. I am always polite, but my test comes when I am in turn treated rudely. I always respond in kind. I don't like that. Working on it.