I try hard not to let things infuriate me. Deal with what I can control and let the rest go. It's a work in progress.
I wish people would search for answers and stop asking the same questions over and over again.
The kind asking for advice or recommendations, but had done zero research and includes minimal context. For example:
Thread: What's a good city to go on vacation for a week where you don't need to rent a car?
Replies: Hmmm Barcelona, Taipei, Tokyo, Prague, Istanbul.
OP: Oh my budget is only $3.50 and I'm from Nebraska and don't have a passport.
It isn't a specific rule (as it's usually covered by "don't be rude" or similar), but I have little to no patience towards witch hunters: users who screech and try to denounce other users, based on little to no rational evidence. Bonus points if the witch hunter has poor reading skills, and extra bonus points if claiming "good intentions" in the modmail (my go-to reply is "go pave Hell with them".)
It infuriates me the most because I got a lot of neurodivergent people in my social circles. And I know that this sort of behaviour makes the space less safe for them, since the ND folks will say things that will be poorly understood by the irrationals, and the irrationals will start screeching at them.
Thankfully I didn't get this behaviour in any of my Lemmy comms... yet.
I don't moderate anymore, but when I did it was the repeat rule violations that irritated me the most. I don't mind correcting people once, or twice, or even three times. But there's a limit. It feels like parenting, just listen to me the first time I say it, please.
Not a moderator here, but in general, what annoyed me the most was people breaching the very first rule in the pinned post / FAQ / welcome post / etc.
Wait, this post reminded me I don't know my instance rules
Well, it was nice while it lasted guys