Lifehacker:

People say that “everyone should work retail or service at least once in their lives.” I couldn’t agree more. Like many people, some of my first jobs were retail service gigs. One in a department store, another in a bookstore. I’ve long since moved on, but I learned a lot about the nature of people—and how that battle between selfishness and empathy is something we all struggle with, every day.

I never worked long in retail but I was there long enough to know the jobs generally sucked. 99% of retail employees are good, hardworking people. Please treat them with the same respect you want for yourself.