What's the pettiest thing someone has ever argued with you about?
I had an interesting interaction with someone who commented on one of my fanmix posts years ago, which you can read here. It's not so much of a petty argument but rather confusing argument? I'm still baffled by the entire exchange nonetheless, and I still think about it to this day. While I can understand the curiosity, why would you even want to assume someone's nationality based on the music artists they listen to? That's just odd.
Also some years ago someone decided to be very argumentative on one of my posts regarding a particular fandom, it was only vaguely in relation to something that I had written about and they suddenly decided to just....rant at me about their thoughts. The thing is, I don't mind talking or even debating about things, but this individual was very aggressive with the tone of their comments right out of the gate, and I tried to be civil and understanding but even when I tried to calmly explain my own thoughts (which opposed theirs) or even tried to deescalate things in order to end the conversation they just got more and more aggressive. At the end of the day I think they needed an outlet for their frustration and unfortunately I was made a target simply because I mentioned that fandom in a post. Perhaps they thought I would agree with them, and when I wasn't they got more confrontational. It was certainly a stressful moment for me since it went on for a few days and I kept grappling with how to handle the situation, since I didn't want to freeze the comment thread nor did I want to upset this person any further. Thankfully, it did come to an end. I don't know where this person is now, but I hope they're doing much better.
(Although I'm not sure whether that constitutes as a petty argument since what was being discussed people do have strong feelings and opinions on which are valid, but the way it happened, with them coming into my post just to rant unprompted and continue on like they were intentionally wanting to pick a fight, certainly seemed deemed enough to be petty. There is a time and place for such discussions, and that was neither.)
Those are just a couple of examples that I still think about. Sure, I have real life examples too, but I think online interactions can create unnecessary petty arguments since misunderstandings happen far too often due to miscommunication and tone cannot be read as easily.