Why is it said in calligraphy that “the book is like the person it is”?

Words are like people, which refers to the true inner expression of serious writing. For example: a bold person writes in a grand manner, a reserved person writes in a rigid manner, cannot let go, has a petty spirit, and women write more gracefully ( This... is not entirely true, and some female classmates are so bold in writing that it scares people to death, haha) These are all external manifestations of one's inner self, which is unconscious. In addition, the man upstairs said that the ratio between Qin Hui and Yue Fei, I think That's one-sided. If Qin Hui doesn't have a bold and generous mentality, how can the prime minister firmly believe that his own is correct? The words written in this way will be correct and elegant, but whether he is right or not is another matter. , just a superficial view, no need to go into details, haha...