INTJs can read intentions like a book. It is why we are known as the master strategist; we can read and understand people's intentions usually from the moment we meet them. We can also evaluate their intelligence and competence very quickly. In fact it is in our nature to make an internal judgment on everyone we ever meet. You literally have about 30 seconds to make a good impression on an INTJ or we usually put you in our "nothing to learn/gain from" list.
At that point you meet our walls. Our walls are actually a complicated and complex machine that is designed so that it gives other people just enough of what they need, in order to reciprocate our needs.
We could absolutely care less what someone thinks of us, our ideas on the other hand are the most important thing to us. We will readily share our ideas with others, and are open to critique, but only by those who are knowledgeable and can teach us new things. We soak up knowledge like a black hole.
If you meet an INTJ and they are being genuine and honest with you, then you are in a very deep level of the INTJ castle. Because we can read people so easily, we usually can give someone just enough so that they have no idea they are not getting all of us.
This is also why we are considered by most to be cold, detached and aloof.
What INTJs cannot ascertain through our intuition is emotion and what it means. We attempt to make logical sense of emotional responses. This could cause us to build walls of an entirely different manner. These walls are actually our unhealthy walls. They cause us to ignore Fe and focus on Ti. This causes many INTJs to become underdeveloped in emotional response and evaluation areas. Which leads to us to distance ourselves from emotion and reacting to it.