Remembrance of hungry times or having experienced the Great Famine are just excuses. When it’s summer, memories of a particularly cold winter will not make you put on more clothes.
It has more to do with selfishness and self-centredness than anything else. The hypothetical case of someone flipping the table over to make sure no one gets to eat is actually rather telling of what goes on in their greedy people’s minds. It’s in their perverted and competitive nature to have a sense of victory by depriving others of their rightful share and getting more than their rightful share. Having unfairly benefitted from what what’s supposed to be a sharing exercise gives these folks the feeling that they have won.
Such behaviour transcends all ages and their numbers may not be as small as this YouTuber may think. I’ll never forget the time I had hotpot in Chengdu. I was told by the waitress that the time limit was 2 hours. I was out of the place in half an hour. First of all, I was almost full and secondly, the food wasn’t that great.
When I passed that restaurant almost 2 hours later, the diners of all ages who had entered at about the same time I did were still gorging themselves silly. I doubt it has nothing to do with their experience with hunger. It’s about winning this game and the objective is to eat more than what they’ve paid for.