I disagree. You are forgetting that some of us quite literally CANNOT speak. As a severe stutterer, I consider mine severe because I block on at least 75% of the words I say and each block lasts between 10-30 seconds. A mild stutter is a lack of any speech blocks at all or very few speech blocks, and consists of occasional or even frequent repetitions and prolongations that in no way affect your ability to get your words out at an acceptable pace.