"It has nothing to do with us, "Han Zixin said, turning his gaze. He also made her look at him rather at the entrance of the restaurant. "Ignorance is bliss. The more you want to know something, the more it will trouble you. Sometimes, it's better to not know anything. Let them handle their own matters."
Although it would be better to have knowledge of things most of the time, sometimes it was better to not know about things. The more you stay away from those things, the better it would be for you.
Similar was the case with Gu Shangyan and Shen Yue. If An Xiulan decided to know their equation, she would have to be part of it, willingly or unwillingly. Therefore, it would be better for her if she didn't raise any sort of questions and mind her own business.