The narrator and the other students are discussing the food in the canteen. The narrator says that the vegetables are all cactus. He says that if he doesn't eat them, he'll get sick. The other students mock him, saying that he's just as scary as they are. They also mock the fact that they're eating vegetables out of the canteen, which makes it sound creepy. They say that they don't have to eat the vegetables, but if they do, they'll inevitably get sick because they've eaten the wrong kind of vegetables. The students mock the idea that they should eat vegetables, and they mock the narrator's fear of getting sick from eating the wrong kinds of vegetables, which is why they eat vegetables in the first place.