As you get older, you often get wiser, if you're paying attention. You've seen this happening before, or something like it. You know what's coming down the pike.
You start to find a lot of drama unsatisfying, because it's written by writers who haven't been around the block, who are making characters do things they really wouldn't do.
The flip side of this is that you start to understand not just how foolish people can be, but in what ways they tend to be foolish. You get to know what sort of blind spots people have.
For example, we're in the middle of a slow-motion train wreck that anyone reading the papers knew was coming, but most people did nothing about. I mean, I knew intellectually it was coming, but I did not e.g. make a killing on the stock market. (Though we did self-isolate a bit early.) We didn't act because other people weren't acting. We didn't act because we have never lived through a serious pandemic, so it all seemed a bit unreal. The last polio epidemic was in the 1950s. The last mass measles epidemic in North America was in the 1960s.
Writing screenplays, you will often need to have characters do something less than logical. Where would horror movies be if at the first sign of horror the main characters immediately left? Where would cops stories be if the cops waited for backup?
(Though one of the things I like about the unnecessarily well-written TREMORS is that the heroes spend no time at all trying to find out why people have disappeared; they immediately try to get out of the valley.)
So what's the difference between annoyingly dumb and brilliantly dumb decisions?
Character decisions are annoyingly dumb when it's obvious they happen because the writers need them to. They are driven by the plot. Hank Azaria calls it the "idiot ball": "who's carrying the idiot ball this week?"
Character decisions are brilliantly dumb when they happen because the characters are human. They make the kinds of dumb mistakes people make. Ideally they make dumb decisions that reveal what sort of people they are.
For JAWS to work, Peter Benchley needs Quint, Hooper and Brody to be isolated on the water. If they can call for help, then the drama is just "will they survive till the chopper arrives?" If they can't, it's "will they survive?"
So Quint smashes the radio. That's illogical, right? But his pride is at stake. He's got his back up against the smart-ass scientist and the bossy police chief. He does not want them to call for help; he's taking it as an insult that they want to call for help. If they get a bigger boat, which would obviously be the sensible thing to do, it won't be his boat. It will be someone else's.
So he smashes the radio. It's a great character moment. It is a brilliantly dumb thing for him to do.
If you've been following politics for the last three years, you've seen a lot of people making dumb decisions out of cowardice, or greed, or pride. You've seen people do things that no sensible, decent adult would do. But adults aren't sensible by virtue of being over 18 years old. Common sense is not common at all.
Tragedy starts with a tragic flaw. It's Odysseus's pride that leads him to tell the Cyclops who he really is after he's beaten him; when complications ensue, he spends twenty years trying to get home.
Hamlet is too smart for his own good. He spends the play trying to find out for sure if his uncle really murdered his father. Put Othello in that role, and he'd just up and kill Claudius on Day One, and take the throne for himself. Done.
Almost every romcom is about how adorable people who are obviously meant for each other fail to get together until they've exhausted all the other options.
In the past twenty years there's been a lot of cognitive science about our blind spots. We see patterns where there are none; hence all the gambler's fallacies. That's because in the wild, 95% of the time that odd thing in the grass is nothing, but 5% of the time it's a sabertooth, and the humans who see patterns where there are none survive, and the people who are too skeptic only have to be wrong once and it's all over.
Read the cognitive science. It's handy both as a writer and as a person to know all the different ways our human brains can screw us up.
So keep that in mind when you're making up your story. You totally can and should have your characters do dumb things. The best drama is about people who can't or won't do the smart, logical thing for human reasons.
Mistakes are what drama's all about; just make them convincing, compelling mistakes that reveal character.