I had the same beliefs you did and thought it was never going away, and I ran into OPs posts a week ago and bought the book and I've already seen improvement. Literally last night I said the word "mobile" in conversation without thinking about it, and I usually block on "Mo" sounds. Seriously just get the book and try it. It works. I used to think it was like bad vision and "that's just the way it is." Funny enough, I wasn't trying to not stutter last night, my speech improved without me being consciously aware of it. I didn't realize I said the word correctly until I stopped talking. I fully believe now that stuttering is a subconscious habit that can be changed, and I gave myself proof last night.