If you were in Tibet, the common parlayance, would be
"but we can't run around telling people that physical manifestations are outside of our brains."
There is more evidence that our dreams are real, and that the 3D world is an illusion. But, we were raised in a country were people don't even listen to their dreams.
I do understand where you are coming from. I was raised in that environment. But I can no longer believe it, as evidence has shown otherwise.
Yes, some cultures are vastly less intelligent than others. If Tibet has a problem with separating reality from fantasy, I wouldn't be the least bit surprised. I myself was raised in a christian household and so couldn't tell the difference until around the time I turned twenty. It's an extremely common mental disorder and you're representing it perfectly.