Along those exact same lines, yes! I am audhd, and that internal anger also helps me stay on task and "forces hyperfocus". Yes its a false bravado, but I have been doing both throughout my entire adult life, and didn't even realize the actual reason for it. It gave me a bit of a sense of relief to find out through a movie that they'd done a similar thing for stuttering royalty who had to give a speach. (Queen Elizabeth's father .... I think the movie was 'all the kings men' )