Just because somebody told you it is incurable doesn't mean that you will stutter forever. It is just their opinion on things in general. And who is to say that they have all the valid information to draw that conclusion (like do they personally know all the people in the world who stutter). People suddenly get cured of cancer and nobody knows why or how. Miracles do happen. If they have not yet found a fail-proof treatment, doesn't mean that one day you will not suddenly and unexplainably get better on your own.