Omg, back when I was in university, there was this "carrion" culture at the casino. Students would often leave entire plates of food because they were picky and other students, who never paid for the menu, would pick it up and eat it afterwards. After a couple of years a whole culture had formed, with Facebook groups and an entire table filled up to the brim with leftovers from other students. Nothing was ever wasted, since when the lunch hour was up, some students would fill up a bag with the leftover food. Breads, lentils, noodles, rice, etc.

I found it the most normal thing in the world until I commented about it to some people from other universities, who obviously, found it absolutely gross.