Heptadecagon

I'm the type of person who looks behind me when I'm standing in line at the grocery store and offers to let the person behind me go ahead of me if they only have a few items. I do this regularly, and many times, people have thanked me profusely for allowing them to step in front of me. I don't mind, really. I think it is the right thing to do, and for the most part, I remember to glance back each and every time I go to the store. This past Sunday, I was at Aldi and had just pushed my filled cart into the line. Of course, two seconds later, I looked behind me. There stood a woman in a red coat with about five things in her hands. Me: Do you want to go ahead of me? Red Coat: Oh, thank you, but no. I'm in no rush today. Me: Are you sure? [I had to ask one more time. It would make me feel as though I'd done everything I could do to make her go ahead of me.] Red Coat: I'm sure, but again, thank you. I proceeded to unload my items onto the belt as another woman, ...