"Shen Youding can't remember clearly" is from "Lovely Bookworm". This article is about interesting things that happened to three great scholars: ① Shen Youding, a famous logician, opened a letter of introduction for marriage registration and forgot the name of his fiancee. The famous philosopher Jin won't be an official and forget his name. The husband of female writer Yuan regards his wife as an acquaintance. The purpose of this paper is to praise these three scholars for their extraordinary dedication to the cause of science and encourage middle school students to have this spirit when learning scientific knowledge.