Why is the content of a commentary book also different from the original?

The main reasons why the commentary is different from the original are as follows:

1) What is a commentary?

Commentary, also known as book-telling, book-telling, Guangdong Cantonese and other regions commonly known as speaking ancient, anciently known as talking, is an ancient Han traditional oral speaking performing art form, began to popularize in the Song Dynasty. The storytellers in different places tell different stories to people in their own native languages, and are therefore part of the dialect culture.

2) What are its characteristics?

The traditional storytelling books that have been handed down are characterized by Han oral literature. It brings together the wisdom of the people, and is the crystallization of generations of storytellers, as well as the fruit of mass artistic creation. It is passed down through the "booklet" (a detailed outline of a book, also known as "Liangzi") and the method of oral teaching. Different schools, different actors on a book characterization, plot arrangement, etc., there are different ways to deal with, especially in the "review", depending on the person, has a great variability. Commentary artists are both actors and authors, their performance process, often is the process of careful conceptualization and continuous creation. This is precisely what characterizes oral literature.

References: Baidu Encyclopedia of Evaluative Books/view/71304.htm#10

Reason 1: From these two points, it can be easily known that the evaluation of the book is a kind of oral literature, since it is oral literature, is a mouthful of each other, it is inevitable that there will be some mistakes in it.

Reason 2: This may also be the second creation of the storyteller, like the novel into a TV series, the novel content will often be due to the subjective reasons of the screenwriter or some external objective reasons, and the original work has some discrepancies.

Reason 3: The difference you mentioned could also be due to the form of storytelling.

I hope my answer can help you, satisfied please adopt, do not understand please ask, thank you O(∩_∩)O~