Si Yuchen's painstaking efforts for Gu Xiaonuan, she will never understand.
In Gu Xiaonuan's eyes, Si Yuchen has always been a selfish, cold-hearted, and rigid person who can't tolerate anyone contradicting him, someone unlikable.
How could Gu Xiaonuan have thought that this guy, whom she detested, would ultimately make a decision considering her best interest?
Si Yuchen thoughtfully considered Gu Xiaonuan's situation, but Gu Xiaonuan couldn't feel Si Yuchen's kindness.
This is where Si Yuchen failed the most because he never wanted anyone to know what he was doing, even if it could improve others' perceptions of him; he still wouldn't do it.
Si Yuchen had his own plans, he didn't need others to understand him, nor did he need anyone to have any expectations of him.
Everything he did was for his own happiness, and it was what he wanted to do.
He strives to have no regrets, and that is his greatest effort.