Now My Head Hurts

This morning I had an appointment to meet with someone at McDonald's so we could talk. I arrived a few minutes early so I went to the counter to get some coffee and had to wait in line. There was a woman with a small child at the front of the line, and after placing her order, she realized she did not have her money with her and told the cashier to cancel the order. I spoke up and told her not to cancel the order, that I would pay for it. The cashier snapped at me, "You'll have to wait your turn!" I said, "I'm trying to pay for her order" and again she snapped at me and told me that I would have to wait. The woman ahead of me, looking like she was in total disbelief,  told me to go ahead of her which made me next in line. So I stepped up and told her that I wanted to pay for her order. The cashier said, (loudly) "It's not your turn! You'll have to wait!"  So I handed a $20 bill to the young mother and told her to pay for her food. She handed the money to the cashier. After counting the change back, the cashier went over to another worker near the fry vats and commented that she could not believe the nerve of some people.  I don't think she ever figured out what was wrong with this whole scenario. And this is the caliber of people who are demanding $15 per hour.