Choose carefully when making friends; Stick to your principles and so on. This idiom tells the story of the Three Kingdoms period, when Ning Guan and Hua Xin were good friends. When they were weeding in the garden together, they saw a piece of gold on the ground. Guan Ning is still waving a hoe, and there is no difference between looking at tiles and stones. Huaxin happily picked up the gold and threw it away. They are reading at the same table. A man driving a car with a shed and skirt happened to pass by the door. Guan Ning was reading as before, but Huaxin went out to read. So Guan Ning cut the mat open, sat with Hua Xin and said to Hua Xin, "You are not my friend."

Choose friends carefully: In the story, Guan Ning expressed her disappointment with Hua Xin's friends by cutting her seat. This shows that we should carefully consider when choosing friends, not only to see whether the other person's hobbies are the same, but also to value the other person's personality and values.

Stick to your principles: When Huaxin's behavior ran counter to its principles, Guan Ning took decisive action. This shows that a person should stick to his own principles and beliefs and not be shaken by external interference and temptation.