Respect
The key to me is respect. Different cultures have different language. For example: When I go into a country restaurant, or a Diner I expect to be a "Sweetie", or some variation of "Hon". That just the culture. On the other hand, when I go to a top floor restaurant I expect to floor treatment. Not the snooty throw the food on the table and leave thing. Two restaurant example to illustrate the point.
What bugs me are two things. First, when they will not believe me. One example was in Denver when the medical folks put drugs on my medicine list I was not taking. "Are you sure you aren't taking these." ""Well, if you aren't, you should be. " Then, there are the people who look me in the eye and either verbally, or by body language say: "Get out of the way you old cripple "
Fortunately both are in the minority. Most of the time people go out of their way to help. Sometimes I need it and appreciate the help. Other times not. But, I want to encourage civility and helpfulness. So I always smile and say "Thank you"
I figure part of my duty as an elder is to reinforce good behavior to overcome the rudeness and self centered that is all too common. That also means me not being so self centered as to get my panties in a twist over truly minor things. Respect.