In fact, Cang Li knows etiquette. This statement first came from Biography of Historical Records and Huo Zhi. It means that when a country's warehouses are full, people know how to observe etiquette. This statement has some truth, because a country's economic development is the basis of its cultural, social and political development. Under the background of economic prosperity, people's living standards have improved, and their cultural quality and social moral level will also increase accordingly.

However, there are also some problems in the saying that granaries understand etiquette. First of all, it implies that people will only observe etiquette when the economy is prosperous. However, in fact, people's moral level does not depend entirely on the economic level. In some countries, despite the economic downturn, people can still abide by moral norms. Secondly, Cang Li Man really understands etiquette, which oversimplifies people's behavior. People's behavior is often influenced by many factors, including culture, society, psychology and personal experience.

Therefore, we can take the sentence that granary knows etiquette as an inspiration to remind us of the importance of economic development to culture and social morality. However, we also need to realize that people's moral level depends not only on the economic level, but also on other factors. Therefore, we need to discuss how to improve people's moral level from multiple angles.

In a word, the phrase "granary knows etiquette" is an ancient wisdom, reminding us to pay attention to economic development and cultural inheritance. However, we also need to realize that people's moral level is influenced by many factors, and we need to discuss how to improve people's moral level from many angles.