Zhang Zhentian decided that he needed to step forward and say thank you to his son and genuinely thank his grandson.
Clearly, this family had already been turned upside down because of him, yet they were always willing to let him continue being part of it. He repeatedly persuaded himself, although he couldn't understand why this was the case. But ultimately, this was the ending he desired the most; no one wishes to return home only to leave again.
Everyone in this family was his kin, and no matter when or where, he should stay close to his relatives, accompany his family properly, give them the warmest feelings and the truest care. Yet, what had he done over the years? Heartlessly abandoned his family and chose once more to leave them.