It's quite interesting/bizarre, but I used to not stutter at all when I talked to myself when I was younger, but some years ago I suddenly began to stutter by myself as well and still do. I just tried reading some of these comments aloud to myself - very disfluent! The change didn't really happen because I started stuttering more in general, though, that didn't change. I'm not completely sure why it did happen though, but I'm thinking it might be because I got much more comfortable with the fact that I stutter and much less sensitive about it etc... Guess it could be described as some degree of acceptance - although I WILL NOT accept, or more fittingly SUCCUMB to giving up trying to get rid of it - goddamnit I would be so happy...