Before the invention of the printing press, literacy was a rare skill. Indeed, until the 20th Century, more people around the world were illiterate than literate.
Surprisingly, in wuxia stories, it seems that *most* characters are literate. When Mo Yung F'uk was revealed to be illiterate (and even then, it was by choice, not circumstantial limitations), it was shocking. Is the high degree of literacy among wuxia characters at all historically plausible?