I believe that all we have in the world are our relationships, maybe hermits are content in their way of life because they never could truly socialize but I don't know about them being fully happy.
What we call shyness to me could be understood as a lack of social intelligence mixed with little self-confidence, both of which you can gain by being out-reaching and taking risks. Not to put the blame on anyone of course because it does take real hard work for "introverts". But again, it is to big a deal to be an oversight and not try to be better in your own way.