I feel compelled to share my current process of understanding and dealing with my own introversion. Maybe this will resonate with others, maybe not. Where I am right now, it's more important for me to be able to share this than anything else.
I ended a relationship recently, partly because we had huge communication issues. Her thoughts were always close to the surface, I tended to think about things for hours before finding the courage or words to express ideas that were important to me. When I finally managed to say out loud what I'd been mulling over, she didn't always take me very seriously or even let me finish my thought before jumping in with hers. This of course made it even harder to open up to her again. I tried earnestly to explain to her that I needed quiet time daily to process my thoughts and that interruptions were lethal to my ability to communicate. In the end she never seemed to accept that this was a fundamental part of my personality and not some excuse I was giving her. Often she would make sarcastic comments like "Have you had enough quiet time today?" These relatively innocuous comments hurt me more than most of our arguments, simply because it communicated to me that she truly didn't understand me or what I needed to be happy. Maybe we could have established that communication, but the relationship had gone on too long for that kind of refactoring.
After the relationship ended, I suddenly had ten times the social energy. I thought I was burnt out of performing comedy, but suddenly had more then enough energy. I took the time to study social skills and took a hard look at my life and my emotional state. It became clear to me that being introverted had closed me off to not only her, but to all my friends and even family. I realized that my closest friends actually made me LESS social, simply because of the attitudes they held towards meeting new people and society in general.
So I started cutting them out of my life. I began a new effort of being more social. I limited my "deep thought introverted" time to when I was actually alone. When I was socializing, I made sure that I extroverted the entire time. If I felt the urge to check my phone or zone out of the conversation, I recognized that my energy had run out, excused myself and left. I made new friends who viewed me as a social, outgoing person. Their expectations of me helped my momentum. I forced myself to be open with people. I ignored my tendency to withhold personal information, embarrassing stories, or questions that might make me look stupid. I started bantering more with coworkers that I hadn't been close to before. I started reinforcing the believe that I shouldn't feel the need to hide anything about myself.
I was a little confused by the new amounts of social energy I had. My girlfriend had taken up a lot of my time, but after our breakup, I was able to maintain a schedule with at least twice the social hours as previously. Where was I getting all this energy? I realized that what was draining me wasn't being social, it was being uncomfortable. It was the awkward situations, not social situations in general, that were sapping my energy. I couldn't tell the difference because I was in a situation where 90% of my social interactions were uncomfortable for one reason or another. In my relationship, I was constantly worried about giving her the time she wanted to spend with me while giving my time to process my thoughts and work on projects. In general, I was always trying to follow a train of thought in my head, even when out with friends, or in a meeting, or in a friendly conversation, instead of being present and happy to interact with someone else.
The biggest benefit to this change in my life has been the increased sensitivity to my own emotional state, including how much control I had over my own happiness at any given time by means of my own posture, facial expression and state of mind. I realized that just wearing a stupid grin on my face made my happier than any of my academic or professional accomplishments. It was as if my introversion had muted me to my own emotional state. I began to recognize that humans are essentially emotional antennas. Evolution has conditioned us to subcommunicate volumes of information to each other. The emotional state of a person is broadcast and received by everyone around them. Extroverts are much more sensitive to this than introverts. Suddenly I realized why smalltalk, politeness, and so many other things I had never given much value were so important. Other people felt the effects of these things a hundred times more than I had. And they couldn't help it anymore than I could help being introverted.
The reverse of this is also true, by learning to recognize this, I began to pick up much more how other people were feeling. Connecting with people and making them happy begin to give me as much satisfaction as I've ever had from programming or making something work. I'm beginning to reconsider whether technical work is good for my emotional state, or if I am even cut out to be happy while doing it.
Am I truly an introvert? Yes, I still believe I am pretty strongly introverted by nature. Do I think all introverts are closed off? No. I think most introverts, even those more introverted than me, are more successful than I was at maintaining at least a few close friendships. I do believe that learning how to be comfortable in ones own skin is critical to being a happy person. I certainly didn't give this problem nearly as much attention as I should have. If you take anything away from this, I hope that you will consider if you should be giving it more attention in your life as well.