Yet your anecdote is within a domain you are already familiar with and strong in. Rather, it depends on the difficulty and the how far the material is from your

Yet your anecdote is within a domain you are already familiar with and strong in. Rather, it depends on the difficulty and the how far the material is from your comfort zone. Never studied math? Take on the state of art in AI research. Never played the piano? Learn a Chopin ballade. Never read much? Consume the cannon of a Joyce or James. Extreme examples, yet I believe it applies to formidable gaps within fields too, knowing a number of PhDs and what they went through: learning things that are both outside of your comfort zone and considered difficult will almost certainly require a significant amount of discipline and head-banging.