What observation does the narrator make about "small children in times of hardship" (39)?

In Chapter 10, entitled The Family Begins to Starve, there is a heartbreaking passage in which the dire nature of Charlie's malnutrition is portrayed. The narrator states, "And now, very calmly, with that curious wisdom that seems to come so often to small children in times of hardship, he began to make little changes here and there in some of the things that he did, so as to save his strength" (39). The narrator expands his claim when he notes that Charlie leaves the house ten minutes earlier every morning so that he may walk to school more slowly and that he now sits "quietly in the classroom during recess, resting himself, while the others rushed outdoors and threw snowballs" (39).