If someone stutters past early childhood, we can be nearly certain that they will stutter to some degree for the rest of their life. People who say that they "cured" their stutter still experience the loss of control and tension that they always have, although the overt presentation of stuttering may have changed. And with that, those people who can change their overt stuttering significantly must continue to use taxing strategies all the time in order to maintain the facade of fluency. I don't think fluency is a bad thing by any means, but it doesn't seem worth it to attempt to use all of our mental/emotional resources to pretend that we don't stutter, and then in the process lose some of our ability to focus on the actual content of the conversation. I certainly do think that increasing in confidence may increase fluency in a natural way - so someone may go from stuttering much more significantly to stuttering somewhat less often simply because they removed the shame, fear, and self-stigma that they've always felt about themselves with their stuttering. But this isn't something that can be easily manufactured and may not necessarily occur for everyone.