There was a bit of discussion about this on a podcast I listen to (Adrift) earlier in the year.

My mind is basically me taking to myself. As I write this I'm speaking all the words in my head. As I read it back I'm reading all the words in my head.

I believe there's a school of thought that you shouldn't read the words to yourself when you are reading, bit I have to do that otherwise it doesn't go in. I can read a page without the words being spoken in my head but I will then have no idea what any of the page said, v and have to re-read it. Same if my mind wanders while reading - anything I read whilst my internal voice is talking about something else will not go in.

I can't shut it up. If I think about nothing, my internal voice will literally be saying "I need to think about nothing. I should empty my mind. How do you think about nothing?".