Everything I Learned in People, I Learned while Bagging Groceries

I've also concluded that about:

10% of most people are extremely kind, generous and appreciative
20% of most people act appropriately polite and say their generic "please" and "thank you" in the way taught and expected
40% of most people don't say much nor smile as if customer service people have been replaced by automatic tellers
10% of most people frown and grumble but it's nothing personally directed to you, just grumpy
5% of most people are on the phone with someone else - either laughing or yelling
5% of most people are yelling or laughing with/at their children/friends
10% of most people are incredibly rude, generally dissatisfied with everything in life and try to find fault and blame by personalizing toward you

My favorite part of my job is when they look at me like I'm a second class citizen.