What are some of the rules about the Internet that were taught to you but are now completely ignored?
For me, it was that the Internet never forgets and that you should never enter your real name. In my opinion, both of these rules are now completely ignored.
Social media killed online aliases and I have a hard time deciding if we're all worse for it.
Instinctively I still stick by that, though, as you can tell by my anonymous profile with no bio, but when I volunteer any amount of personal info these days people are often confused that I'm not sharing openly who I am or where I'm from. Every time someone does that it weirds me out because in the 90s telling (and asking) people those things would have been such a suspicious, sketchy move.
Basic forum etiquette. It's horrifying at work seeing teams "teams" (forums) used like chats, all the cross-posting and thread necromancy, people completely unable to keep topics confined to the appropriate sub-forum, etc
The same people who warned us about the dangers of the internet and not to believe everything, are now the ones readily falling for and spreading conspiracies and lies from social media.
I learned as a kid playing star craft that there are noobs and newbs. Newbs are people new to a game who need help learning. And a noob is someone who has played for a while and refuses to learn and would rather troll.
As in real life, it's pretty sound advice to ignore, block or otherwise disengage from trolls and other forms of belligerents. Even in the '90s when I first started using the internet, the phrase of the day was "don't feed the trolls". But people just can't help themselves. They will even reply saying "I know you're a troll, but...".
The Steam forums are a great example, where every other thread is a fake "is this game woke??" screed. The fact that you can be rewarded for being a cunt there with jesters (which translate into points that can be spent to buy profile items) just makes it a thousand times worse. You get 'paid' to be a troll on Steam. It's insanity.
The only anti-troll weapon that works or is needed is oblivion. Let their steaming turd of a post curdle in solitude. Don't even downvote it. Being downvoted is a victory for them, an acknowledgement that they exist and that they've gotten your attention and that they've annoyed you. Shadowban them from your mind. Block them so that no future posts of theirs will infect your screen. Report them so mods can remove/ban them. Just don't engage directly with the post or the user. Don't say "blocked and reported" in the troll's thread/post. Just do it silently.
Sticking around and "lurking" for a bit before you try to engage with a new community, to learn the local etiquette before you make an ass of yourself. Or at least reading the rules as a bare minimum.
There always have been the nick picks. But now sometimes there is barely any connection between the post and the comments. Like two people with multiple strokes distributed between them having an angry teams call.