When I worked at a sandwich shop for two years, I learned the value of good customer service. I actually enjoyed it. Making people laugh or smile made my day. Our work emphasized good customer service a lot, so now when I go into a restaurant or store and the employees are short with me, appear bored or are just not doing their job, it bugs me a little.
On the other hand, I know there were more than a few days when I felt sick at work, or was exhausted or had stuff going on in my life and it was very hard to paste on a smile for other people. So I can see it going both ways.
But I agree with everyone else, RobinAnn, there's a difference between what you did - which is totally acceptable - and what a lot of *cough* may I say younger workers out there today do. (I'm younger, so I think I can get away with that..>_>)