I think it kind of depends on who you are as a person, and where you live. I've worked in a grocery store for roughly 2 years now, and I've very rarely had any of these issues I always hear people talk about. I think that if you give out good karma you receive good karma in return. Obviously if you're there and act like you're better than your job, hating it, and would rather be home, it's going to drag on and people will probably notice that and see you as an easy target and treat you poorly in return. Sure, there are annoying people, but usually you're able to palm them off to someone else after dealing with them for a short while, and have them deal with them - which you'll find after it's done, it'll turn into a funny story to tell people rather than something to make your blood boil. I hear so many stories of people complaining about their jobs and customers, and I've just never experienced it; not sure if I'm just lucky or if people are exaggerating.
Where I work is the busiest store in the area, largest flower supplier, and is located in a relatively rich part of the area, so we do get a fair few of uptight customers, but it's really nothing intolerable. Though I feel like if I worked in a more communal, suburban area it would be different. That said, I do live in Australia, and my view of America is very stereotypical, sculptured by how the media portrays it, so I'm assuming it's not going to be nowhere near the same as it is there as it's a completely different culture. What I'm saying is, despite everything I hear about it, I've never really experienced those issues.
