Well, I'm getting to know you a little, Bella, and you seem like a fairly deep ISTJ to me.
I've known my ISTJ husband since I was fifteen. He always looked to me like he had already found himself and knew who he was and what he wanted. But, over time, I have realized that he too, is in process of becoming his true self. And, while he has never said, I like to think that it's important to him.
He just doesn't verbalize it - ever. I doubt that it even occurs to him. He isn't much of a metathinker. Pretty matter-of-fact about things.
And when it comes to feelings, he keeps it simple - mad, bad, sad, glad. That's it. No complexities there. Any more would put him on overload, I think.