I don't have a problem expressing myself here, or many places. My social anxiety is only brought on to a frightening degree in school settings, from many many years of abuse from junior high throughout highschool. I thought it was toughening me up and that it would make me stronger. I tried to ignore it and not let it bother me, and for many years I believed it didn't bother me. I tried to deal with it on my own, giving the kids the finger from time to time when provoked, standing up for myself verbally, and it only spiraled more and more out of control making things worse, until a point where I wished I had told someone or asked for help, because the magnitude of it was far more then I could possibly fight back against on my own.
Now almost done University I have had the hardest time of my life.
I applied to University believing I had overcome my problem, and so far from my hometown there hasn't been a single chance of encountering any of my antagonists. But I surprised myself when I became completely unable to speak in the class settings. My antagonists no longer needed to be present to torment me and beat me down, because my mind now did it for them.
And away from school right now I can tell you how stupid and cowardly I feel I become in class, and can tell myself just to toughen up, like I wish I could, but it is a whole different story once I am on campus. I am subconsciously scared to death of letting myself get bullied again to the point which I was that I am not even able to will myself to uninhibit my actions and words in school.
I totally see your perspective though, I used to think the same way, and sort of still do, but I now realize how hard that advice is.