There's a popular mythology in our culture that most people are naturally outgoing, extroverted, and socially adept. We see this on television, on the Internet and in social media. Having eighty thousand friends on Facebook is both an inside joke shared by millions and a grotesque caricature of what it means to be successful as a person.
Successfully executing our responsibilities at work is generally measurable, and our professional relationships come with definable rules and boundaries. Our professional roles are essentially mapped out for us. Our roles as social animals derive from social mandate, creations of what we should be. It's only natural to conclude that we're "supposed to be" friendly when we're with other people, particularly when we're with people we don't know. When being around other people causes subjective distress, we wrongly assume that there's "something wrong" with us, that we're "different," or that we "don't fit in." Civilization relies on "getting along" for its survival, and one unintended consequence is that we're trained to play-act when we're in certain situations. This, in turn, produces undue anxiety in anticipation of our being around other people.
Many of us can't wait to get home from either work or social outings so that we can just be ourselves. Yet we are, after all, social beings. But this doesn't mean that we have to be social beings of any particular type. Societal norms and expectations can rob us of our individuality by counseling us to act "normal," even though no one seems to know what "normal" is. They stunt our personal growth, sacrificing individuality in the service of not rocking the boat filled with people just trying to survive yet another social gathering.
Being shy, quiet or introverted are not symptoms of pathological states; they are, instead, attributes that often suggest strength of character, thoughtfulness, and even wisdom. Being or acting cautious, reserved and distrustful around people we do not know carries survival value and is part of our evolutionary history. Many of us have had the experience of meeting someone who comes on too strong during a first contact, and it's never pretty. There's a sense that something's "off," and we can be left feeling uneasy for the experience.
Ideally, personal and social relationships exist in negotiated space in which two or more people can express themselves as honestly as they care to do so, and within certain limitations or boundaries. The expectation, or rather, the demand, that we should act in certain ways in order to make everyone else happy or to satisfy someone's expectation is unreasonable, sometimes rude or destructive, and only encourages a special kind of deception.
Personally, I'm most often drawn to the most quiet person in the room, even though I don't always approach them.