Reading Susan Cain's Quiet is plenty enlightening and assuring. If you simply understand and are at peace with how your introverted self thinks, behaves and instinctively responds, then you're more likely to find balance in this hyper-connected social time we live in.
Why does an introvert usually shun social gatherings, novel situations and even just getting out of the house? One, he is highly reactive and sensitive to his environment. Feeling things more deeply, he can be overly stimulated and more exhausted. Another thing is that he prefers meaningful relationships and thinking more deeply about things. Perhaps he hasn't learnt to interact and speak up with multiple parties at once, and doesn't like being labelled anti-social. At the very least, he prefers friendly and cooperative group settings.
Can an apparently extroverted person actually be introverted within? Yes, as he has learnt to project such a persona, whether motivated by work obligations or a cause he passionately pursues. He is usually highly observant and empathic, even towards a group audience. This is however demanding and energy-sapping for him, that's why he's got to find "restorative niches" to recharge himself.
He could even make a great leader. Because he is astute, listens well, takes carefully calculated risks, is persistent, and probably appreciates how other introverts operate and will afford them the space they need to thrive. Many fine examples stand out in human history, belied by whatever front we remember of them: the fiery, oratorical sort; the unassuming, behind-the-scenes worker; or the powerful, letter-writing influencer.
Coming to a place of self-awareness and self-acceptance is definitely key to finding personal happiness in what he does for a living, how he manages his time and energy everyday, how he complements and makes compromises with his life partner, how he deals with conflicts and stressful situations etc. Otherwise when confronted and overwhelmed by fear, guilt or anxiety that is triggered by others voicing their criticism or venting their anger, he shuts down his natural empathy and becomes avoidant.
Well, the world needs both introverts and extroverts, Cain reiterates in her book. And they both need each other. The extrovert very well seeks meaningful lifelong relationship which he finds possible with an introvert. The introvert finds conversation with the extrovert easy and interesting. Effective, well-considered decisions are made with the inputs of both achievement-oriented and properly analyzed views.
Learning all this makes me feel more at peace and hopeful of applying myself well in life. It's timely because I'm realising that my priorities include paying attention to the nearest and dearest around me--and not money, career success or material possessions. All the better if I can relate better to my family and close friends, be they introverts or extroverts.