I think he means that the brain does exist, but that our brains don't have a perfect model of the real world or physics, hence our dreams look like this. Also,

I think he means that the brain does exist, but that our brains don't have a perfect model of the real world or physics, hence our dreams look like this. Also, in a way, comparing GenAI/LLMs to how our brain neural nets work (which isn't exact, but have similar outputs).