You hear voices while you dream. In my dreams, other people talk without me controlling what they say, so obviously they have their own internal voice independ

You hear voices while you dream. In my dreams, other people talk without me controlling what they say, so obviously they have their own internal voice independent of mine, yet they all live in my mind. (People I know tend to act like I'd expect them to act. They're the embodiement of my perception of them in real life, but autonomous.) I've always found that strange that people could live in my head during dreaming. What's more, I sometimes dream of people doing creative things or creating stories. Yet those things obviously come from my own brain. I can't figure out how my brain does it. It's smarter than my conscious self.