Then why else do you think you stutter? i stutter myself but it's quite literally all in your head, you don't stutter if you don't think about it. The more you focus on it and think about it the worse it gets. My evidence is my personal experience, that of my dad and psychiatrist. They all stutter and my physciatrist said the exact same thing that if you wanna make improvement you gotta tackle the underlying issues since there's nothing wrong with your speech.