I don't either, but my general awkwardness and quietness probably says otherwise. put it this way, at the moment i work in a cliquey workplace, its very hard to adapt to that even for the best of personalities. at home its also a difficult place to relax in. But i have found some places where i can relax and i can talk to people.
Look to be honest i think its an environment issue. some people are suited to certain environments (work, home, education, etc) that suits them but many are in environments that dont suit them or they can't adapt to it, that's the issue i think. Once that becomes a routine and a habit then progress is pretty difficult. so finding the right environment/head space/lifestyle/whatever is the key.