Liu Chan, the son of Liu Bei, is often called "not thinking about Shu". This allusion originated in Luoyang during the Three Kingdoms period. At that time, Wei Jun entered Sichuan, and Liu Chan, the last ruler of Shu, surrendered and was sent to Luoyang. Si Mazhao named him the Duke of Happiness, gave him a house, gave him a monthly allowance, and had a hundred servants. Liu Chan made a special trip to thank him, and Si Mazhao hosted a banquet, singing and dancing. When the music of Shu started, the old ministers of Shu recited the sadness of the country's demise, and all of them burst into tears. Liu Chan, on the other hand, is insensitive and laughs. Si Mazhao said, then ask Liu Chan; "Do you want to relax?" Liu Chan replied, "This place is very happy. I don't miss Shu. " Hearing this, Zheng Gu, his old minister, quickly found an opportunity and whispered to him, "Your Majesty, when Si Mazhao asks you again, you will cry and answer,' The ancestral grave is far away in Shu, and I don't miss it every day!'" "In this way, you can let your majesty go back to Shu." After hearing this, Liu Chan kept it in mind. Halfway through the wine, Si Mazhao asked again. Liu Chan soon understood what the tree was teaching him, but he just wanted to cry. Hearing this, Si Mazhao said, "Hey, why does this sound like what Zheng Gu said?" Liu Chan said in surprise, "You are absolutely right! Si Mazhao and his ministers all laughed. Si Mazhao saw that Liu Chan was so honest that he never doubted him again. In this way, Liu Chan spent the rest of his life happily in Luoyang, and handed down this hilarious allusion of "no fun".