For me, it was in the linked blog post
>"Now, anyone who has read Mindset by Carol Dweck, Grit by Angela Duckworth, or The Brain That Changes Itself by Norman Doidge, M.D., knows that you can be, do, and have whatever you want."
The gap between "read" and "understood" swallows so many. Also, did he use TR's "Man in the Arena" quotation? Reader, of course he did.