I yesterday chatted with a guy who goes to a speech therapist. The therapist said that the main problem and possibly the reason why we stutter is because we think about every single word we say or want to say. When we feel "free", when we speak fluently, we think only of the idea, not exact words. I personally think that this might be the right answer and main focus- getting rid on such was of thinking. Haven't practiced it yet as found about it only yesterday.