Part of why both kids and parents love The Very Hungry Caterpillar is because it’s an educational book that doesn’t feel like a capital-E Educational book. Traditionally, children’s literature is a didactic genre: “It teaches something,” Martin says, “but the best children’s books teach without kids knowing that they’re learning something.” In The Very Hungry Caterpillar, she adds, “you learn the days of the week. You learn colors. You learn the fruits. You learn junk-food names. In the end, you learn a little bit about nutrition, too: If you eat a whole bunch of junk food, you’re not going to feel that great.” Yet, crucially, none of the valuable information being presented ever feels “in your face,” Martin says.