I have a non-verbal inner voice which gives meta-commentary on my verbal inner voice. If I want to think about what I’m thinking, that’s what is going on.

I’m one of the 5-10%. I always sucked at verbal memory tasks. Didn’t know some people have an real, interpretable internal monologue until a few years ago. I thought thinking nonverbally was the default. I even specifically remember watching shows and movies where you listen to a character’s internal internal monologue and thinking “this is dumb, that’s not how thinking works”. Turns out it is, and I’m just in the minority! Now I make an effort to manually start an internal monologue when I’m doing anything that requires a lot of verbal processing, like listening to instructions at work. It helps, but I can still tell that I have a deficit compared to most people when it comes to those things.