I'm not doubting your opinion, but lets say its neurological, wouldn't I also have trouble when speaking to myself out loud? I'm 100% fluent when no one is listening, but once I know that someone will listen to what I have to say, I stutter. So theoretically if I could ignore the presence of the person that is listening, I would be 100% fluent, but I doubt that this is possible to do on a daily basis.