This sentence ostensibly praises his good memory, but actually criticizes "I" for being too careless in reading with humorous language and euphemistic tone. This brief language description reveals Mr. Lu Xun's implicit, humorous and humorous personality characteristics. It can be seen that Mr. Lu Xun is kind, generous and humorous. He is educating "me" in a special way. It can be seen that Mr. Lu Xun's education and requirements for the younger generation are strict.