As a cashier, I once had a customer who was upset about a certain brand of chicken which was on sale. I could tell that she was upset as she approached my register, given her overall demeanor. I was able to confirm that she was indeed upset, as she became argumentative with me once I had scanned her items and given her the total. She proceeded to demand that I page a manager, which I did, then listened as the manager came over to explain the sale to the customer, She then further made a fuss, and though she purchased her items, I apologized to her for the confusion, and thanked her for shopping with us. Several days later. she came to the store once again, and made it a point to go through my line. During the checkout process, she reminded me as to who she was, and proceeded to apologize for her previous behavior. She told me that my professionalism and courtesy had reminded her that she was taking her own personal problems out on a total stranger, who had nothing to do with the reason she was upset, and that she had felt badly about it ever since.