After reading this entire thread which made me laugh and made me shake my head, I have a few things to say:
1. I guess what amazes me the most is the fact that people act as if they are entitled to be rude if the situation doesn't grant them what they want. What happened to treating others as you would like to be treated and common courteousy? (rhetorical question, don't respond..

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2. It has never occured to me, EVER, that I should put the divider up for the next person. I had no idea that there was a protocol for this.
3. I will do what I can to be a courteous shopper. If I am unintentionally rude, my apologies... What happened to waiting your turn like the rest of us? I do not care if you are in a hurry. Your lack of planning does not constitute an emergency for me.
4. If you have a couple of items, use the express lane, don't stand behind me because there are 10 people in the express lane and act like I owe it to you to let you go first. If you are polite, I might let you go in front of me, but chances are, I have already waited my turn and would like to get home too.