> If you write an essay about each thing you come across, you'll have to learn the stuff to some depth.
I took the author to mean a much more active pursuit when they spoke about learning — applying the technique to the stuff you're consciously trying to understand better, rather than just any new info you come across.
That said, the depth/length of "write about what you learn" could be tailored to how much weight you want to put behind it — writing could be as little as a thoughtful comment on HN or a tweet as well as a blogpost/essay.
I took the author to mean a much more active pursuit when they spoke about learning — applying the technique to the stuff you're consciously trying to understand better, rather than just any new info you come across.
That said, the depth/length of "write about what you learn" could be tailored to how much weight you want to put behind it — writing could be as little as a thoughtful comment on HN or a tweet as well as a blogpost/essay.