I had an inkling about your question, and now I can articulate it: You don't have to be able to explain how you got the answer, but you do have to be able to

I had an inkling about your question, and now I can articulate it: You don't have to be able to explain how you got the answer, but you do have to be able to explain *a* way to get the answer. Minsky said "You don't understand anything until you learn it more than one way." In proving theorems in mathematics, there's often an intuition that it's true, and even why it's true, but still it needs to be put into a formal proof. But it's very hard to arrive at a proof, by thinking in formal terms, because the search space grows exponentially. Intuition is a shortcut. But you still need to go back and work out the formal proof, to show you're right - to yourself and also to communicate it to others. And, once you know the answer, and have an idea of why it's true, this guidance makes it much easier to find your way. To come back to your question: you can learn another way to get the answer by watching videos, where they explain what they are doing as they go. So, this won't explain how you do it, but you can learn another way of doing it that you can explain. BTW IMHO the most insidious difficulty in learning mathematics is gaps - an incomplete or subtly incorrect understanding. It's insidious because the gap is not apparent at later material, because it assumed, so you won't know what you're missing, and therefore can't diagnose or fix it. You need either an excellent teacher/tutor/mentor/coach to pick it up (but they often don't), or to methodically go through all the previous work. The sooner you do it, the easier the easier it is.