Introvert Survival Guide

Many of us are surprised to find later in life that we are introverts. This is particularly confusing for those who are outgoing and socially skilled. How did we miss this all our lives? Aren't introverts the shy, socially awkward people who dislike going out or being among other people? The introvert revolution has shined a light on a lot of misinformation and lack of information about us. However, the stereotypes of introverts as wallflowers, computer geeks whose only interactions are online, and crazy cat ladies still abound. For one, not all introverts are shy.
Some of us are, but not all. And we don't all choose to spend time with our cats instead of people, though some do. So, who are we and what makes us who we are?