There was an article on FR earlier today about an old guy attacking a wheelchair bound man in Walmart for going through the 20 item express lane with 22 items.
We have a new HEB grocery store here, and there is always a person who directs shoppers ready to check out to the most available lane. When we were ready to check out just before Christmas, the lady signaled us to go to the "express lane" even though we had an almost full cart. They work hard to get shoppers checked out.
Some years ago in Minnesota there was a story about an old, retired guy who had a cabin in the woods next to a lake. The old guy had his own boat ramp. Some people from the big city bought some land next to the old guy's property. The people had some young kids sub-teens or around that age. During the summer the kids took to playing on the old guy's dock. The old guy warned the family to stay off his dock. The kids kept playing on the dock even after repeated warnings.
Well, one time after catching the kids playing on his dock, the old guy went out and shot the kids and then went and shot their parents. Apparently many old people have a much shorter snapping point than younger people.