Why do christians come in the store as if we should worship them?

I work in a grocery store and these people come in there on sundays right after church. It is so annoying, they come into the store with their expensive suites and perfumes. They act as if we should be at their beckoning call. One guy yelled at me because I slid his M&Ms down the conveyor belt. He said I crushed them. Nothing annoys me more than the ones that come in and try and pass you one of those little pamplets. Another thing that really urks my nerves is when I say "have a good day" and the response I get is "You have a blessed day as well"... I'm thinking to my self "THATS NOT WHAT I SAID!". I'm a fellow christian, but really, whats their deal?