> Scholze avoids getting tangled in the jungle vines by forcing himself to fly above them: As when he was in college, he prefers to work without writing anything down. That means that he must formulate his ideas in the cleanest way possible, he said. “You have only some kind of limited capacity in your head, so you can’t do too complicated things.”
Grigori Perelman also worked this way. According to "Perfect Rigor" (Google Books link: https://goo.gl/tFe6hP):
> Perelman did his thinking almost entirely inside his head, neither writing nor sketching on scratch paper.
Frank Lloyd Wright is known for working in a similar way [1]:
> Still another remarkable quality about Wright’s work habits was his practice of never doing a sketch until he had the entire project worked out in his head.
Actually, Feynman answered in an interview once that his notebooks were where he did his work. The interviewer followed up with something like "You mean where you wrote it down?" and he gave an emphatic no. Ah, here it is:
> Weiner: Well, the work was done in your head but the record of it is still here.
> Feynman: No, it’s not a record, not really, it’s working. You have to work on paper and this is the paper. OK?
It was nice to see this because that algorithm, even if meant as a joke, never sat right with me. The Feynman of the lectures would not encourage you to believe in magic.
Grigori Perelman also worked this way. According to "Perfect Rigor" (Google Books link: https://goo.gl/tFe6hP):
> Perelman did his thinking almost entirely inside his head, neither writing nor sketching on scratch paper.