I had that experience at our walmart the day before Thanksgiving, and then again today. Sure it was a madhouse both days, but people were actually trying to be helpful. There was one tiny little thing today tho. I was in line at the checkout.... NOT express, and had about half a cart. I noticed a man behind me only had 3 items and no cart.... so I asked him if he wanted to go ahead of me, and he did (thanked me, of course) but then as he was being rung up a buddy of his showed up with about 10 more items and put his with the first guys. I never said a word.
First guy turns and apologizes to me, and I laughed and said, "No. its okay, the longer I'm here, the more time Hubby has to spend with the kids!" and everyone in line laughed.... and Buddy of first guy thanked me..... and all was well. No biggie, just kind of odd.
It was a nice change of pace.