Living leisurely in Tang Dynasty Chapter 40 Discussion

It's so good!!!

I wasn't aware he was changing the course of history untill I read another review and I'm 40 chapters in.

I read a bit about the history of those guys on wikipedia, but the changes the protagonist makes are so subtle (while he himself is just a normal human from those times) and the plot progresses so slowly, that the reader isn't aware of the history being changed.