It basically seems to me to be when a group of people are given the option of two conclusions: they are misquoting/incorrectly remembering, or, reality has altered. Then they go with the latter conclusion. It would be shocking to me, but these days nothing humans think or believe shocks me any more. These days I'm shocked beyond belief when someone makes sense.
One of the funniest(saddest?) videos I saw(was forced to painfully watch) was a guy showing the label as it "used to be" compared to the label as it "now is" and claiming that reality had changed. Somehow no one bothered asking(or, even thinking) if reality changed, where did he get the example of how it "used to be"? I was like this:
Then when I noticed my friend was looking at me with a baffled seriousness; I was like this:
Even if it were real, I wouldn't at all be impressed with the knowledge that somewhere out there are infinite versions of me buying Jiffy instead of Jif.