The official script of "bowing one's head and willing to serve as a child" appears square. According to relevant information inquiries, the art of calligraphy has a long history, with official script being square and regular script being dignified. "Self-mockery" is a seven-character poem written by the modern writer Lu Xun in 1932. The first couplet of this poem describes the dangerous situation the author was in at that time. The chin couplet writes about the action of persevering in struggle. The neck couplet insists on the inner motivation of struggle, that is, strong love and hatred. The fourth couplet writes the determination to fight to the end. The whole poem has strong internal logic, interesting writing and solemn content.