People who have delusions or people deep into their conspiracy theories have an insane level of insistence. They will refuse to accept "That's just not how that works" as an answer. It's scary.
As Philip K. Dick said, of his own "laser pointer" incident: "If you were me, and had this happen to you, I'm sure you wouldn't be able to leave it alone."
Remember, that even for us healthy people, there's ultimately no objective answer to what's important or not. There may be more or less objective conditional answers (e.g. if it's important that I don't starve to death tomorrow, it's important that I eat), but those already assumes something is important. It has to bottom out in something that's important for its own sake, something whose importance can't be justified from something else's importance.
I think the "gangstalking" people have had experiences that their mind does not allow them to dismiss. They may be capable of accepting different explanations for why the experience mattered - but they can't accept that it isn't important, because it's somehow a root important thing for them.
In that very same Philip K. Dick essay, he more or less apologized for this, and listed up various different explanations that he'd tried. But he was lucky enough that his "ultimate importance" experience was basically pleasant. The genuinely paranoid people are not so lucky.
I had a friend experience a psychotic episode and suffer from delusions. It was more than just, "this is really happening to me". Any suggestions that we offered that they weren't able to refute became part of the delusion. "You're right, it's not the police breaking into my house, it must be the FBI!"
I think the big surprise of the internet and subsequently the SCP wiki's focus on cognitohazards and "killer memes" is that the phenomenon in it's own way is an extreme version of a real danger - as a species we are really not well equipped for the information environment we've built, and it's prudent to tread very cautiously.
https://aeon.co/essays/how-the-psychiatric-narrative-hinders...
https://old.reddit.com/r/Gangstalking/
Here's a fascinating Aeon piece on the phenomenon
https://aeon.co/essays/how-the-psychiatric-narrative-hinders...
For many people with mental illness, it's not a "refusal". That implies agency and deliberate choice from a properly functioning mind. When it's the mind itself that is malfunctioning, those kinds of verbs don't really work. The very definition of "delusion" is a thing you are compelled to believe even in the absence of evidence. If you are able to stop believing it, if you are able to not refuse to change your belief, then it's not a delusion in the first place.
Further, some people suffering in this way have anosognosia, which means not only are they delusion, but their mind is also incapable of perceiving its own malfunction.
Both the lasers and the meteors have in common the fact that there are far more false negatives than true positives.
Who's convinced by "lol no ur stupid"?
If you can't explain why it doesn't work that way, there's no reason anybody should believe you.