I think everyone who’s ever been taught to cook meat gets told to sear it “to seal in the juices” and ensure your steak etc is juicier. Well, this is a furphy.
In a cook book, back when cook books were a rare thing, a guy wrote this as the reason for searing meat. No one ever questioned it, and in the way of cooking knowledge it just became a part of cooking lore.
Since some scientists did tests and showed that this process does nothing for moisture content, they’ve figured out the benefit is probably the creation of tasty ‘browning compounds’ that form on the outside. So it’s still worth doing.
Just not for juiciness.
But it’s a great example of how, if something is written down and no one has reason to question it, it can become something absolutely everyone ‘knows’ is true.