You have to teach yourself.
Because in traditional settings there is one teacher and dozens… even hundreds of students. Nobody is going to sit next to you and ensure you understand every detail. And even if they could, they would fail, because when you aren’t teaching yourself, learning becomes a passive, and not an active, activity. Your brain becomes less engaged. You put little energy into it. You may catch a few factoids from the presentation, but that’s not learning.
In High School I got to do a senior project on whatever topic I wanted. I chose Cinematography. I didn’t even know what the word meant. Something to do with film making.
But over the year I was the teacher. I taught it, I learned it, and I remembered it much better than the other things I picked up that year.
Nobody can own your learning but you.