When i talk to myself i often stop at words i usually stutter at ans then i remember"Wtf dude you can say it now" and i just say it. I tried the same mentality in front of people but it didnt work(i probably couldnt enter the same mindset). Seems to me its a pretty obvious that the issue is a psychological one. Although i wasnt a stutterer my entire life (started at 15ish and im 22 now). Not sure about people with severe stutters since birth. I doubt theres something wrong with my brain or my vocal chords.