He Nanran thought that he had gone back to the past and had been with Xu Xingchen earlier, taking that person's place and being with Xu Xingcheng, experiencing everything they had experienced. He knew it was shameful for him to steal everything from that person, but he still chose to do it without hesitation.
The thing that Chen Nianran regretted most in his life was that he lent his reading card to a girl out of kindness, which led to the girl's tragic death. Chen Nianran suffered from this all his life because the girl's brother Cen Mubai resented her and thought she had killed his sister Cen Nianran.
Purpose: I want to go back to the past because of regrets