Had a bad experience today, and it's not the first time. Were two in front of me, and the cashier was very nice to them and said, "Thank you, have a good weekend" in a pleasant tone. The same to the guy behind me. To me he said "have a good weekend" in not a pleasant voice". The difference in attitude was huge, he was positive and happy with the others, with me he was the opposite. To protect myself I will never again look at the cashier. I am aware of my face expression. I'm always nice and polite to people I meet for the first time, but that will end now.