Stuttering is weird for me too. I only stutter after a period of stress or lack of sleep or both. It can start in the middle of talking to someone and it can take ten minutes for it to go away or sometimes it will take a week. For me it has to do with my eyes. My right eye is a lazy, but I am right handed. My brain is then confused, because it thought that my right side is my best side, but my right eye won't work well. Because of the confusion in my brain and my lazy eye that can't go away (because I am too old), my brain will make me a bit clumsy and it makes me stutter. So for me it has to do with neurological stuff, so maybe for you too.