My daughter works in retail and said she had some guy curse at her because she told him that they could help him at the cashier's counter and there was a long line. I told her I would have said, Merry Christmas to you too, pointing out how sad it was to see him act like a toddler. But she simply called her manager over to deal with the grown man and his temper tantrum. My Grandma worked with special needs kids. If she heard any of us curse, she would reprimand us and tell us that we were more intelligent than that. That those were the first words special needs kids learned.
I know I sound old fashioned but they used to teach us in Kindergarten to wait our turn in line and to treat each other with kindness. If a 5-year-old can exert that kind of self control, so can an adult. Just saying. I hope your week is filled with random acts of kindness. Cheers~