There's a lot of weight carried by that thing everyone knows, the thing everyone knows so surely that they don't even know they know it. The sheer tonnage is immense.
Why is a thing true?
Is it true because everyone knows it and there's an explanation that makes sense to you?
That isn't good enough, though.
When everyone knows something and it's wrong, there's always an explanation that makes sense to most people.
It just ain't right.
What I've noticed is that people believe on familiarity. You can show how someone is mistaken, and give them a better explanation, and they can even see it.
But guess what? If it doesn't feel comfortable, if they aren't quite sure about it, if they're just more used to the old explanation, they'll go right on back to it.
You don't believe so much because a thing makes sense. You feel it makes sense because it's familiar. And when you feel it makes sense, you believe it. But that just means most belief is a translation of familiarity.
Plenty of things that make sense aren't true.