Traveling by sleeper train home, middle bunk.

The person in the neighboring bunk has a mischievous kid who started pounding on the wall from the moment they got on the train, like providing background music for the high-speed rail. I endured for about ten minutes, but I really couldn't take it anymore, so I shouted at the wall twice, "Stop knocking, okay?" but they just pounded even more enthusiastically.
I casually hit the wall with my hand and added, "What are you knocking for?"
The next second, a woman rushed over like she had been stepped on her tail, looking furious: "Who’s kicking the wall?! You scared my kid!" She pointed at the lower bunk and asked if it was him.
The guy in the lower bunk looked completely confused, totally caught off guard.
I directly said, "I was the one knocking, so what?"
She instantly snapped: "Just a little kid knocking on the wall twice, do you really need to overreact? He's only 7! Are you sick for scaring the kid to tears?!"
Then her husband also came over, and the two of them took turns shouting, their voices loud enough to be heard in three carriages away.
I kept my tone relatively calm: "I don’t even know if it was the kid knocking."
They didn’t listen at all and continued loudly accusing me of having no humanity.
I sighed and kindly added, "Well, with parents like you, no wonder the kid is so poorly raised."
As soon as I finished speaking, the two instantly lost their composure, took off their masks, and started swearing loudly, cursing in a string of obscenities.
The train attendant watched for a while and surprisingly tried to calm me down first: "Young man, don’t be like that. Kids are kids..."
(My internal monologue: ????????)
I continued to smile: "It’s okay, I’m not angry even if they curse at me. After all, with parents like you, this kid is probably doomed."
This completely set off the father, who rushed over and almost made a move: "Have you ever been a father? Are you married? Do you understand kids? Do you have a future? Are you Tsinghua or Peking University?!"
I didn’t say anything, silently took out my student ID from my bag, and gently placed it on the small table.
(The card has the words "Tsinghua" and "Peking University" plus "Graduate Student in Progress")
Suddenly, the air was quiet for two seconds.
The expressions on the couple’s faces looked like they had hit a pause button—going from furious to shocked, then embarrassed, then trying to find a crack in the ground to hide in, all in one go.
Finally, the man squeezed out a sentence: "…You shouldn’t talk like that either."
I put the card back and replied calmly: "I don’t want to be like this either, but you insisted on putting me in such a good position."
Throughout the whole process, I didn’t raise my voice, didn’t curse, didn’t make a move—just calmly played my part.
Later, the guy in the lower bunk secretly gave me a thumbs-up.
It’s really satisfying, but more exhausting.
Some people, unless you press them to the ground and rub them raw, they won’t realize they’re not that important.
(The End)