I think it's possible that people experience the same things, but observe them differently, so it sounds like they're having a completely different experience.

I think it's possible that people experience the same things, but observe them differently, so it sounds like they're having a completely different experience. While I can absolutely have a conversation with myself inside my head, I don't "hear" the voice in my ears. Some people might take the "hearing" part very literally. It reminds me of a conversation I had with my sister as a child. We were both falling asleep in a very dark room. I noticed that with my eyes open, staring into darkness, there was a kind of static noise pattern overlaying my vision. I asked her if she had the same thing. "No", she said. "I just see black". Thinking back, it's likely that we were both experiencing the same thing, but she just wasn't observing the same things that I was.