That someone was hurt by what you said does not automatically mean that you "fucked up". Individual feelings don't magically override every other thing in the world.
You're right, individual feelings don't magically override every other thing in the world and that's why if you do something that hurts someone else, then that's traditionally considered a "fuck up" - i.e. a mistake that hurt someone (assuming they weren't intentionally trying to hurt someone, as that wouldn't be a mistake).
If you're in a comedy club and a comedian makes a joke that upsets you, well, you're in a comedy club. It's not about you being upset, it's about the comedian making people laugh. If you're so upset that you can't enjoy it you should leave. It's unfortunate that you're upset but it doesn't mean the comedian made a mistake.
I don't see the distinction you're making here. If someone goes to a comedy club expecting a funny night out, and the comedian starts joking about something that seriously affects them (like a rape joke), then they'll usually leave or keep quiet anyway because they're upset.
But that doesn't mean the comedian didn't fuck up. Sure, I'm assuming here that people don't intentionally want to hurt others and in that case doing something which you think is harmless, that ends up harming others, would be a fuck up.
Suppose I have a clown act and people come to see my show. At one point I squirt water from the flower on my chest and it fires off in a random direction, soaks someone's brand new phone and ruins it. Sure, the person can just leave, the clown show is to entertain people and it does, people find it hilarious that my act has ruined this dude's brand new phone. Does that mean I didn't fuck up because my act fulfilled its purpose? Of course not.
If you're in a classroom and someone says something you disagree with and it makes you uncomfortable, that doesn't mean they fucked up either! You're taking part in an environment that promotes the exchange of ideas for educational purposes. If you're afraid of being exposed to ideas that you may disagree with, it's not the place for you.
I think you've misunderstood the topic here, nobody is talking about being afraid of being exposed to ideas that they disagree with. That has literally absolutely nothing to do with triggers.
The point of asking for trigger warnings is precisely so discussion can occur without hurting someone and interrupting the discussion by having them have a panic attack or episode, or have to leave the room in the middle.
Basically, anyone who isn't on board with trigger warnings is essentially scared of new ideas and perspectives being put forward, which obviously has no place in a university.
That some of us may be fragile does not mean that the rest of the world must come to a halt. It means that you'd better go buy yourself a nice padded suit, or hang out in a padded room, or buck up.
But nobody is asking the world to come to a halt, what are you talking about?
The main themes in this thread are: 1) triggers warnings can be useful, so if you're about to give a lecture that involves graphic discussion of rape, maybe start it by saying: "Just so you know, some discussion of rape will be occurring today", and 2) if someone is hurt by your actions, that's a shitty thing even if you didn't intend to hurt them.
Neither of those things require a "halt" to society. The first takes 2 seconds in order to allow a full and open discussion where nobody gets hurt and everyone gets exposed to new ideas and new perspectives, and the second requires you to do absolutely nothing different since it's just a description of a causal relationship (if you do X and X hurts someone without your intention, it is called a "fuck up").