How to know if you are an Introvert or an Extrovert?

Introvert vs Extrovert

From early childhood all the way till the age of around 22 I remember being introverted in my outlook and orientation towards people. Avoiding public gatherings, feeling a sense of shyness while introducing myself to people and remaining quiet most of the time specially when I am in a group of people, these and many more such instances had become a norm for me. It was after a series of experiences that in a way turned me fearful of people, I decided to embrace change. I began exploring the social side of life. I am now touching 27 and in the last 4 years I have successfully turned the tables around and I can write this with no doubts that today I am a people's person (no exaggeration intended)
Although the reason behind why I changed is a long story in itself and not relevant to this discussion too. However, in the capacity of my introvert-turned-extrovert experiences I can jot down a few points that may help bring clarity in knowing if you are an introvert or an extrovert.

1. As an introvert (or so to say) I was never sure about saying YES to attending an event where I will be seeing many unknown faces. Whenever someone use to invite me for a party (or any like event) where most of my fellow attendees would be strangers for me, my immediate natural response coming from within would be a sense of awkwardness. Today, when someone calls me to join for a similar gathering I feel neutral most of the time and in some cases I feel excited too
2. This may be an unusual indicator but a couple of years back I use to avoid putting my picture on social media accounts as well as on any messenger apps as opposed to today, where I am quite comfortable with it
3. When I have made a new friend and if at all that person asks me general questions (just to get the conversation started) I use to feel as if he/she is getting personal. This use to make me perceive them with an eye of suspicion. Today, I do not feel that anymore. On the contrary, I would admit that in most conversations, I am the one who takes the initiative of getting the conversation started and I am quite active in asking general questions in order to know more about that individual (I stay away from asking questions that have a possibility of making that person feel uncomfortable in talking to me, that way I am mindful of being under my limits)
4. You meet someone new, you both talk for a few hours and then after a couple of days or may be a week or two you see this person again, would you take the initiative of saying a 'Hey, What's up?' or would you remain passive and expect him/her to greet you?