For the sake of experiment I tried to avoid having an internal monologue / dialogue but it's surprisingly difficult. I'd be curious to hear if people have succeeded here and what that does to you. Are you still able to function and grow as a person and a thinker without that inner chatterbox? Can you think without vocalizing it in your head?
And yeah, interesting fact, I'm an introvert and an only child too, like some of the other posters. I've been the only person I could regularly talk to my entire life. I'm sure that has a huge impact on this.
In other words, it is really strong - To the point that when I first tried meditating, I found it extremely frustrating. The instructions I had didn't tell me what to do with the inner monologue. Somehow I was supposed to concentrate on breath without using it and I honestly couldn't figure out how to go about such a thing. I've never really understood why folks want to be without it.