It might be rational to agree to disagree :) It would be naive to believe in something without having a proof that backs your point. I've been stuttering since roughly 7, so probably ~13 years now, at least from what my friends and parents tell, it was quite bad when it started, and got so much better now, it seems that I've changed quite a lot, especially mentally. If it would be curable, then we would cure probably most severe disorders, where brain works a bit differently than it should, which researchers seem to be finding lately. Although I can agree with the fact that it's in our head, public speaking would cause me slight problems, as with other situations, not so much 😊. Not accepting the scientific facts may be rough, but I hope you find your way to your authentic self, even while stuttering ❤️