Zhang San Confusion

So we have been seeing Zhang San's diary at the end of the episodes. I am confused. It looked like it was showing what happened to our main lead, Xiaoho Dan, in his childhood. But then again, Zhang San is Dan's son. However, the flowers seemed to have been planted by Dan, and he even called the Dowager Mother. I am very confused, please help. I watched the anime season ,1 but not properl,y so I might have missed things in the anime too. 

 evilpeach:

Our ML's real name is Zhang San in the real world, and he got transmigrated into Xiaohou Dan's body since middle school. The actor who plays ML as a child was also used to play the current crown prince.  I guess it's convenient and since they're father and son, it makes sense they look like each other (so they can use the same actor to play different roles :D).  Dan and Zhang San are the same person, he was the one who planted those flowers. It was not the current crown prince, he is a different person entirely lol

OMG did they use the same actress to play the dowager and grand dowager too? this has been confusing me for a whle.