Zheng's early fairy tales still belong to the category of children's books, but people will become. People who read his books will grow up one by one, and Zheng's books will change from children's books to adult books. The content of his book changes with the generation. At first, the pure fairy tale world has disappeared. The content in his book contains more cruel aspects of this society, such as violence and blood, which are not suitable for children who are being enlightened.
What's more, when children are naive and kind, they should accept the kind of positive energy, not the stories with too many negative emotions. Although Zheng's starting point is good, for most parents, they want to give their children the best, let them know the darkness of reality in the future and let them grow up happily, instead of knowing the cruelty of the world from the beginning and obliterating their innocence.
In particular, Zheng popularized some adult physiological knowledge for children in his book, which is not suitable for children to read. There is also the book "Cpaing and 4 19 Crime". Although he wants to popularize legal knowledge to teenagers, it is not something that children should know at this age, and it is not suitable for children to read, so some parents are reluctant to let their children read his books.