I overthink everything, to the point that it's actually not useful at all. I have to have a conversation or write things down to get my thoughts actually clarified, and it leads to a lot of worrying and anxiety.
I have at least three or four thought tracks running at any one time in my head as well so I get easily sidetracked because I can only focus on about one and a half at once. The others are there but I'm not really paying attention, they are background noise. I easily forget things, especially when they are important.
I talk a lot, too, waffling and going off on tangents.
My mum calls it "chatterbox brain". I find it really difficult to empty my mind of thought, you know, how you have to do for meditation or yoga. The technique where you imagine a sky and put all the thoughts onto clouds and float them away helps, but I have to concentrate on it and it doesn't work to isolate a thought thread. The only way to do that is to talk or write. I talk (out loud) to myself when I'm alone.
I suspect more recently that I actually have ADHD which is what makes it difficult for me to sort out all of the constant noise in my brain.
Actually I'm not really sure this isn't normal - I mean everybody has multiple "voices" inside don't they? Not in a multiple personality kind of way, just in a sort of "Well, what about this?" "But no, because of that" "Have you considered the other option?" "If I followed option A then X, Y, Z would happen, but if I followed option B then X won't and Y might and Z is unlikely" (except they don't actually "say" all of that because they don't need to talk using language because it's all me, so it's like those individual ideas flitting back and forth in a split second and I have to almost grab them to slow them down and look at them.)
But then I didn't really know until recently that most people don't have a song stuck in their head 100% of the time. That it's more of an occasional annoyance for most people rather than a constant kind of internal soundtrack.
I've just realised it's really confusing to try to explain how your brain works.