Your job should not dictate your attitude. I've worked in many different fields, and always deal with difficult people. I (literally) get called a Mother****** every day at my job, and I still maintain a positive attitude. It's this belief that, BECAUSE you work with the public that can sometimes be rude or annoying, it is your right to act disrespectful back to them. That's not how it works. If you're going to work around people, you need to be a people person!