Why did he leave the hospital?
Ye Di died, their child was gone. Wen Lan was accountable for all those unfortunate events, so he went after Wen Lan like a lunatic and never returned.
"I was going after Wen Lan. I wanted to expose her, but then the car accident happened. It was five years later when I finally regained consciousness. By then, your mother had taken all the blame for Didi, Chunbo was with his uncle, and he was growing up fine. I thought that maybe I should rest my case since everyone was in good hands. I could keep her company and watch over Chunbo silently."
Nalan Jing managed a rather bitter smile. After the woman he loved died, he spent the next five years lying unconscious on the bed. All the dust had settled and all the crowds had gone by the time he woke up.