There was a bit of a collective online astonishment over the publication of some article about some people having no internal monologue. I felt little surprise because as far as I can remember, I've considered it to be something I would call "the narrative voice." Our thoughts (I believe) are like a thunderstorm, and what we recognize as narrative voice is only the lightning.

The refinement of thought into a distinct form. It's the art we make in our own heads. One of the arts.