Consistency is key, if you keep doing something, given that the method is correct, you will get good better, there's no doubt about it.
And that stands valid for almost everything; in my case, programming, understanding math, doing excercise, socializing, etc.
However, this is as simple to understand as it is to forget, so I want to write this idea down to come back to it in case I feel like giving up on something that only takes time to accomplish.
For the record, today, in the morning I wasn't able to wrap my head around calculating a tangent and bitangent from some coordinates and then a normal vector to make a TBN matrix, as explained here. But, after a couple of hours I was able to understand what was (mostly) going on.
Of course, this would've been a hell of a lot easier had I known algebra in a first place, but the point still stands, because even though I didn't understand anything at first, in the end I got the hang of it. And this also applies to 日本語, there are tons of words that I just couldn't remember, but since I kept immersing and doing my Anki reps everyday, I don't forget them anymore.
Future me: you are capable of understanding anything, as long as you seriously make some effort to. Perhaps now it looks like you know nothing, but with time, you will be able to understand a lot more than you do know. That is, as stated earlier, as long as you KEEP GOING.