There is also a short story, that is, two children talk about the day when the sun is closest to us, and one says that the morning is big and round; One said it was noon, baking the earth, and asked Confucius passing by. Confucius can't speak, the child said, how do you know? Confucius' apprentice also asked his master. Confucius said honestly that this is a matter of attitude: knowing is knowing, and not knowing is not knowing. This is what a wise person should have and is wise. Teach us not to pretend to understand.