Czar:

I rather like your statement "I have now accepted that not only am I a confirmed introvert, but I am not and will never be a respectable grown-up."

I, too, am an introvert and it has taken me a long time to accept. I believe introverts digest information, rather than discard. Yet, there are times when others find me aloof, when in fact I don't cater to chit-chat (unless nervous).