In today's parlance, "I" and "I" are synonymous. In fact, there are still differences between them. In the Song Dynasty, there was a copy of the "Four Books", which said that "I" refers to myself, such as "I know what I know"; to others, it is "I", such as "I have a humble man who asked me." The difference here is subtle. However, this is not a very important thing, because "I" is rarely used now. This kind of subtle difference is enough to know as a little knowledge, and it is harmless ...