All is reps. There’s no substitution for reps. 10,000 hours is just a metaphor for reps. Chess is reps. Painting is reps. Thinking, wisdom, even prayer is reps. There’s a reason the French say ‘apprendre par cœur’ (to learn by heart). Repetition itself is the stairway to heaven
If you even slightly entertain the thought of failure, you give your mind a chance to start noticing reasons to fail. But if the only option on your mind is to win, then the world seems to conspire in your favor, because your mind will notice opportunities it wouldn't have before. Become delusionally optimistic, not because it's realistic, but because it's effective. It drastically increases your chances of success.