Introversion / extroversion has to do with how you renew your energy, not necessarily how much you enjoy being around other people.
I have taken the Meyers-Briggs Type Indicator three or four times and have continually scored as an INFJ (I am a perfect split between Perceiving and Judging, but in the event that you "tie," the standard is to go with J - Judging). But regarding the Introvert/Extrovert dichotomy, I am about as pure of an Introvert as they come. My score for the I (introversion) was extremely high while my score for E (extroversion) was practically non-existent. Despite this, I am not exactly a monk and no one has ever considered me shy when they meet me. I have no problem talking with strangers and am very friendly and outgoing with people in my day-to-day life.
Info about introverts/extroverts:
"The preferences for extraversion and introversion are often called as attitudes. Briggs and Myers
recognized that each of the cognitive functions can operate in the external world of behavior, action, people, and things (extraverted attitude) or the internal world of ideas and reflection (introverted attitude). The MBTI assessment sorts for an overall preference for one or the other.
People who prefer extraversion draw energy from action: they tend to act, then reflect, then act further. If they are inactive, their motivation tends to decline. To rebuild their energy, extraverts need breaks from time spent in reflection. Conversely, those who prefer introversion expend energy through action: they prefer to reflect, then act, then reflect again. To rebuild their energy, introverts need quiet time alone, away from activity.
The extravert's flow is directed outward toward people and objects, and the introvert's is directed inward toward concepts and ideas. Contrasting characteristics between extraverts and introverts include the following:
* Extraverts are action oriented, while introverts are thought oriented.
* Extraverts seek breadth of knowledge and influence, while introverts seek depth of knowledge and influence.
* Extraverts often prefer more frequent interaction, while introverts prefer more substantial interaction.
* Extraverts recharge and get their energy from spending time with people, while introverts recharge and get their energy from spending time alone."