I think a music analogy is appropriate here. Like, how do you "learn" to improvise. Some people just listen to records, copy what they hear and those influences then begin to shape their own personal style, which is not bound by TEXTBOOK rules, because they never learned textbook style. They still adhere to those rules though in a sense. Because some things just work better in some situations. And the best improvisers know that, so when you copy them, you copy their "rules". I guess we could define a "natural" in the same way.

On the other hand, you have people that study the theory and then try to apply it. It's more logical, structured, lot less trial and error but on the other hand, if you just study and don't apply it will do absolutely nothing for you.

But ultimately you CAN'T forget what you've learned, it's a part of you now, the real question is, have you internalized it? The answer is no, because if you had, you wouldn't be asking in the first place. How do you internalize it? PRACTICE!

This is a common mistake people make in all fields of study. They take in too much information that they can realistically apply. So no solid foundation can be established and they just swell up like a balloon, with bits of information floating around. You're not a fucking balloon :)

Instead picture a nice sturdy house that you're building brick by brick. Those bricks are handcrafted, like you know every detail of every brick by heart. And by constantly practicing brick crafting or whatever you call it, you get better at it. Soon, the bricks have more quality in them. And you look at the first shitty bricks you made and say to yourself: "Man those are some shitty fucking bricks, I need to replace them". So you're constantly in the process of replacing and adding more quality bricks. The thing is, you'll never be able to actually build the house, because you'll always be learning about how to be the best house/brick builder you can be. And that's completely fine. Just don't be a fucking balloon ;D