Some days i forget that i stutter and then it suddenly dissappears until i remember it again. when i m alone in my room talking to myself i dont stammer. Also when playing sports or playing videogames I personally think that stammering is nothing physical, but some habit that is deeply rooted in our consciousness that we have to “unlearn” somehow, For me it is like breathing, when you remember that you can breath manually it will be difficult to switch to automatic again. When you will “remember that you stammer, you will stammer until you forget the habit.