It turns out that the newly moved neighbor is his high school classmate Lu Nong, whom he hasn't seen for a long time. After greetings and asking how have you been these past few years? Lu Nong replied that sometimes it was good and sometimes it was not.
It wasn't until a woman suddenly shouted in front of the apartment door that Lu Nong and his family were murderers that Meng Huaixu understood the meaning of this answer.
Intention: Destiny thunders, but it turns out to be suffering