Where did people call themselves Laozi come from?

Originally named after Taoist Laozi, it gradually evolved into a proverb. Regarding the origin of the appellation of Laozi, some people put forward that "if Laozi's surname is Li Minger, why not call it' Mei' but' Laozi'". For this question, there used to be a saying that "I was born with white hair, so I was named Lao Zi". It is not enough to believe this legend. However, according to the textual research of ancient philologists (1900- 1986), he thinks that there was only the "old" surname in ancient times, but there was no "Li" surname. Li is the last name, which means that Lao Tzu is old. As a family statement, it helps to broaden people's minds. What does the word "Lao Zi" mean? There have always been different opinions and no one can agree. Because there is no final conclusion, people will inevitably expect literature, which not only affects people's in-depth understanding of this great philosopher in ancient China, but also affects the foreign exchange of China culture. J Macy, an American scholar, made a joke that "Lao Zi's name means' old boys' or' old child'" because he didn't understand the culture of China. Even Russell, a great thinker who has a unique study of China culture, even translated into The Old Philosopher is inappropriate and unsatisfactory. According to Biography of Historical Records, "Lao Tzu's surname is Li, and his name is Er." From the same passage in Zhuangzi, formerly known as Lao Dan, and later known as Laozi, I can be sure that Laozi is Lao Dan. As for why it is called "why not call it' Plum' but' Laozi'", it seems that it really needs to be discussed. Judging from the word "old", Shuowen: "Old, test also. Seventy years old. From people, hair and knives. The words must be white. " Shang Chengzuo's Yin Ruins: "(Oracle Bone Inscriptions) is like an old man walking on a stick." In addition to this old man with white hair and beard, he also showed respect to some courtiers in ancient times. "Thirteen Years of Zuo Zhao Zhuan Gong": "Old Tianzi, please be handsome." Du pre-note: "The doctor of the son of heaven is called old." In this case, it seems that both the image of riding a green ox with white hair and beard and Sima Qian's reference to his official position "History of Zhou Shoucang" should be regarded as a kind of honorific title. Ancient philologists mentioned in The Four Prefaces to Laozi that there was an old surname but no Li surname in ancient times, whether it was "Zhuan Xu's son had old boys" in Shiben, "Sima Lao Zuo" in the 15th year of Zuo Zhuan's book, or "Lu had Situ Lao Qi" in the 14th year of Zuo Zhuan's book. As for "the old man, followed by Di Zi and old boys" in Custom Yi Tong, it is far-fetched and insufficient for later generations. Furthermore, it seems far-fetched to draw the conclusion that there was only an' old' surname in ancient times and no' Li' surname. Because according to the feudal patriarchal clan system in pre-Qin, only the fifth generation concubines can change their surnames. For example, Confucius' ancestors changed his surname from Zi to Kong. After Wei, his fourteenth ancestor, surrendered to the Zhou Dynasty, he was named Shanggong and founded the Song Dynasty, thus becoming the first generation monarch of this vassal state. Later, Fu Cha, the ancestor, declined the change from "Gong" to "Qing" until he lost his status as a "Gong". It was not until the Confucian family of the Five Dynasties did they "not work as a public family" according to the provisions of the Zhou Li, that is, people took five clothes and set up another family, taking its word as their surname, forming the family name of the Confucian family. Then, Lao Zi, as the History of Zhou Shoucang, is neither "public" nor "clear", but just a librarian of Zhou Tianzi, and has nothing to do with the establishment of five clothes, so it is difficult to establish the statement that "Li is the last name". As far as "Zi" is concerned, Confucius, Youzi, Ceng Zi, Yoko, Mozi, Zhuangzi, Keiko and Gaozi all added the word "Zi" to their surnames, which is the general name of ancient literati. Such as "The Six-year Biography of Ram Gong Xuan": "The son doctor is also." He Xiu's note: "The ancient scholar-officials knew the son." To sum up, "old" people are not surnames, but honorifics with "zi", which means senior scholars.