The thought that what he was reading was something written by someone who had experienced it was something Ning had thought about long ago.
Hearing about blue oceans and green grasses, something that didn't exist on any of the moons, was something that he couldn't just believe that someone had come up with it on their own.
They either had to have read something about that beforehand. He believed that the author must have read some other book that referenced this or was simply born with these memories.
Hell, he even once thought if the author may be a reincarnated individual, who was using his past memories to write a book. However, reading how everything seemed to be a real experience of the author, written in his current life, made Ning wonder just what was going on here.