Throughout my life, I've been confused about the answer to one of life's most often-asked questions:
This is especially true if you minor in psychology, as I did. You're constantly taking tests and analyzing your own personality as part of your daily coursework. I graduated without ever learning the answer to the question.
My mistake was in assuming that an introvert had no social skills whatsoever. An introvert would sit quietly, introspecting, while an extrovert would be chattering away. All too often, I've found myself fitting that "chattering away" description.
Finally I came to terms with the difference. It's not about how you behave when you're face to face with other people. It's about how you feel when you're face to face with other people.
An extrovert feels energized and happy when around other people. An introvert feels energized and happy being alone. Two very distinct differences. Nervously filling silence while standing at the cash register at the grocery store does not make you an extrovert. It just means you're conforming to societal norms.
What's interesting is that writers don't have to be introverts to succeed. There are quite a few extroverts in the field. They tend to excel at marketing and promotion, loving the feeling of sitting at that table at bookstores, signing books. They also are more likely to be typing away at Starbucks, comfortable being surrounded by other writing extroverts.
Are you an introvert or extrovert?