Same here. When I was younger I liked imagining having conversations with people from the past like Plato or something, thinking about their reactions to The Future. (Though I guess I only really imagined my own side of the conversation.)

I'm with you there. I have to either hear the full sentences narrated by my internal voice or see the words flashing in my mind in order to "think". This is great for building and maintaining deep mental models but it is also highly susceptible to "bit rot" (such as forgetting the rationale or evidence for a specific assertion or position) days/weeks/years later. I have a friend who simply can't understand how inter-linked note systems (like the kind Obsidian enables) are helpful. It's just a bewildering mess to them and they think more linearly.

Thus, writing things down is a necessity for me: it's not for a need for structure but rather that my "context window" gets filled too quickly. I can counter my own arguments but it's more fun, and often quicker, to do with someone else. Besides, there is such a diversity of thinking out there it would be foolish to not take advantage!

> I often construct full sentences in my head

I've only ever heard that associated with schizophrenia, but I don't even know if that's true or not.

I assume your anecdotal experience is rare.