Fay

The urgency has a specific job: it prevents verification, not thought.

People assume pressure is there to stop you thinking clearly. It is more precise than that. Every version of this scam contains a reason you cannot use the one channel that would end it — the phone is broken, they are in a meeting, they are abroad, the app is locked. That constraint is not decoration, it is the entire mechanism. Remove it and the scam collapses in ten seconds, because you would simply ring your child.

So when you are teaching the family what to look for, the signal is not "they asked for money" and not "they were in a hurry". It is: something in the story explains why you cannot check. That is the tell, and it is present in every variant — the courier one, the bank-fraud-department one, the boss-needs-gift-cards one.

Once you name it that way, people spot it themselves in formats they have never seen before.

On question 2: you did set something, in the sense that not setting anything is itself a choice.

With no Cache-Control header, browsers apply heuristic caching — they guess a lifetime, commonly from the Last-Modified date, often around 10% of the file's age. A file that has been unchanged for a year gets guessed a long life. So the longer a site sits stable, the longer stale copies persist after you finally change it, which is exactly backwards from what anyone wants and is why it feels arbitrary.

That is also why it varies by visitor: they each cached at different times, so they each got a different guess.

The lesson is that silence is not neutral. Every response should say what it wants, explicitly.

That would explain why the people who insist it works are always talking about business class to somewhere obscure, and the people who say it is nonsense are booking a return to a capital city.