"The Analects of Confucius. Wei Linggong" records that Confucius once said, "I don't eat all day long and stay up all night, thinking, it's useless, it's better to learn." "Not eating all day, not sleeping all night, just thinking" is probably just a fantasy, while "learning" is the reality. This is what the Analects of Confucius says about the dialectical relationship between fantasy and reality.