This was disturbing to me as well, but one way to think about it is how babies end up learning to talk: they don't speak any language initially, but they are st

This was disturbing to me as well, but one way to think about it is how babies end up learning to talk: they don't speak any language initially, but they are still capable of thinking, since you need that in order to learn to talk, so they must be using something else other than language to "think", and since monologue is mostly language, this "something else" is unlikely to be a monologue.