Why is Zhang Fei's grandmother surnamed Wu?

Much ado about nothing = = Wu lives and flies.

The master has a line from a comic dialogue: Zhang Fei's mother's surname is Wu, and Wu's surname is Fei. There is another line: so what are the surnames of Zhou Yu and Zhuge Liang's mother? ! Isn't it? In the < < gt > novel, Zhou Yu, who was angered by Zhuge Liang, felt helpless and lamented: Since Yu was born, why should he be born glamorous? After all, Wu's Flying is a misunderstanding, or a joke made out of nothing in the past, but it provides rare materials for scholars and experts who study linguistics and rhetoric.