Why is Wukong surnamed Sun in Journey to the West?

Why is Wukong surnamed Sun in Journey to the West? It has long been explained in the original work that when Mr. Wu Cheng'en was writing this novel, he had already begun to pave the way. After all, the monkey named Sun began to spread from the beginning, and stories about his grandson began to appear, mainly in hell, which opened the prelude to his opponent's paradise.

In the original book, the Monkey King jumped out of a stone and had no name. It was not until he sailed from Dongsheng Shenzhou, not far from Wan Li, passed through Nanzhou, arrived in Xiniu Hezhou, and learned from Fangcun Mountain that he got his name. The general content is like this.

When Monkey first entered Fangcun Mountain, he didn't know the rules and jumped around, which made other disciples in the mountain quite disgusted. But Bodhi's father kept smiling and asked for anonymity. The monkey said he didn't have a name, and Bodhi's father said he gave it a name. The monkey liked it, too, and finally got a name for himself, so it was quiet.

It's like this in the original book. The ancestors said that although you are humble, you are like a monkey eating pine cones. You and I will take a surname. Yan Zi went to find a wild animal, but it was a Gu Yue. The ancients were old, the moon was cloudy, and the old yin could not be repaired. Why don't I teach you your surname, Sun, and be an animal. It's a subsidiary, and the son is a man, and the baby is fine. Consistent with the baby's theory. Teach you your last name. Hearing this, the Monkey King was filled with joy and kowtowed upward. Very good! All right! . The founder said that there are twelve words in our school, and you are ten generations. These twelve words are: great wisdom is really like the sea of nature, with profound enlightenment, and you are the word of enlightenment, so why don't you call it the Monkey King? The Monkey King smiled, ok! All right! ?

This is the origin of Monkey Brother's taboo. However, it is this Pandora's box that opened the world's reputation. During the training period, its inferiority was exposed completely. Later, the Bodhi ancestor foresaw that he would get into trouble, so he said those cruel words and drove him down the mountain.

After Wukong went down the mountain, he smashed the stalls of the other six sages, then made a scene in hell, and then made a scene in heaven, and typed out Sun's name.