It is you. YOU have two brains, the right brain and the left brain. They are connected by the corpus callosum. I think when I'm emotional I hear the left side of my brain because in that moment... i am the right side of my brain. When I'm being very logical i hear the right side of my brain speaking to me... while I'm currently being the left side of my brain.
I don't know if I said this theory well, but there it is.
and @sunshinebear, I had my theory all along, but wanted your theory not to be biased by my own. Your theory is simple and lovely <3
So I just did some research that bolsters our theories. It turns out that aphasia (lack of internal monologue) happens to 25% to 40% of stroke victims. This may be adequate yet slighly anecdotal evidence that the two hemispheres of the brain are talking to each other... but more importantly that your consciousness can shift between the two hemispheres of your brain. holy shit.
On another note, I think the two hemispheres of the brain have something to do with deja vu. Something with the info of what's being experienced and being stored automatically like it was already there yet it is just now happening. lol sounds good anyways
That is pretty amazing stuff! Nice job looking into it further!