If you don't know your personality yet, then take the quiz here, but it's long, so read this first then take the quiz.
I have taken endless personality quizzes on several platforms and every time I have been an INTJ. This means that, statistically speaking, I am part of only 2% of the population and only 0.8% of women are INTJ.
Finding your personality is amazing because all your behaviors are explained and now you know what to work on to be a more complete person. When you take these quizzes and receive your results you'll receive a long list of traits, but I have decided to make a much smaller list with far less words. Since this will be brief you can find the rest of the information here.
As children
INTJ kids love to find hiding spots so they can be alone with their thoughts. My mom says that, as a child, instead of hanging out with all the kids at the pool I would go to an isolated area and just quietly enjoy the water, but to me, I was creating worlds in my mind.
INTJ kids also read and read and read. These are the kids that ask "Why is the earth round?" and if you tell them "That's just the way it is" they'll ask "why?"
In life
INTJs enjoy introspection and introverted intuition which means that we think, and think, and think. We think about our social interactions, a book, our family, our life, and anything else; when in social situations INTJs can leave their thoughts but the brain is constantly looking for things to analyze and study.
Being social is easy but being social for long periods of time is draining. The only way to recharge is being alone. We aren't hermits; we are actually pretty good socializing but we would much rather read, write, create artwork, and listen to music.
Weaknesses
I feel like I'm exposing myself, but here it is ...
INTJs are arrogant, overly analytical, clueless in romance, and hate blindly following rules. Being introspective can cause us to become a little self-absorbed (yes, that was painful to admit) and since analyzing is as instinctive to us as breathing, we often overthink. This leads to missing many signs in romantic interest.
Funny story, when I was 15-years-old there was this guy who really liked me and several times expressed an interest in really liking me, but I missed every sign because, well, my mind was somewhere else. It wasn't until two years ago I put all the pieces together...it took me 4 YEARS TO FIGURE IT OUT!!
Emotions
Emotions to an INTJ are fiercely private and are only expressed to extremely close and vetted friend. INTJs experience emotions but trying to get them to talk about it is like unlocking an impossible vault that changes combinations with every try. Emotions are viewed as weak and INTJs have managed to control their emotions in a public setting.
Me in public: OMG I feel like I'm going to have an emotional breakdown *eyes start to water*
My brain: