Andrej Karpathy says that effective tutoring made his own ability to memorize the only meaningful constraint on his learning, rather than access to knowledge or adequate explanations.

“or too trivial and a tutor is really good at serving you just the right stuff and so basically I felt like I was the only constraint to learning like my own I was the only constraint I was always given the perfect information I'm the only constraint and I felt good because I'm the only impediment that exists it's not that I can't find knowledge or that it's not properly explained or etc”

“etc like it's just my ability to memorize and so on and this is what I want for”