Reminds me of the description of Peter Scholze as he was coming up with condensed mathematics. Didn't write a thing until he had it all worked out in his head (which is how he always works). Knew if he didn't get it worked out before the weekend he'd never be able to build it up again. Once he worked it out, he was able to retain it for months until finally writing it down.
https://www.quantamagazine.org/lean-computer-program-confirm...