In this article, I am going to explain my adapted version of the notecard system.
Note that he explicitly calls out that his is an adapted version of a preexisting thing--namely a system that was taught to Ryan Holiday who was taught by Robert Greene.
Presumably there is both some economic and street cred value for the author/influencer in claiming his precedents.
It's worth noting that he mentions other famous users, though only the smallest fraction of them with emphasis up front on his teachers whose audience he shares financially.
“The Indexers pose with the file of Great Ideas. At sides stand editors [Mortimer] Adler (left) and [William] Gorman (right). Each file drawer contains index references to a Great Idea. In center are the works of the 71 authors which constitute the Great Books.” From “The 102 Great Ideas: Scholars Complete a Monumental Catalog,” Life 24, no. 4 (26 January 1948). Photo: George Skadding.


