In the winter of 1751, the French thinker Rousseau fell seriously ill. After passing through the critical moment of life and death, he made up his mind to change his lifestyle, such as throwing away his sword, watch, gold-rimmed clothes, and white stockings, leaving only a short wig and a coarse sweater. So why did he keep the wig when he didn’t want anything expensive? 　　In ancient Greece and Rome, hair was a symbol of status, and those in power wore braids. The Romans even planned to have Parliament pass the “Bald Edict” to prohibit bald men from running for parliament, and bald slaves could only be sold at half…