Rather than simply memorizing chess games, they read old games and tried to predict what the next move would be - which the intermediate players didn't do (or at least not very much).
So if you want to be a business grandmaster, you may have to read the businessbooks in an entirely different way from what everybody else does.
His point was that memorizing notes wasn't going to help you pass; you had to actually work on solving problems in order to really learn the material.
That's why I (author of the essay) added that you have to look at the case studies and ask yourself what you would have done, how that could be applied to other situations, etc. That's the only way to build reusable mental patterns (IMO - not sure if there's scientific evidence for that! except mental practice of athletes, musicians, etc...)
Too bad I had a word limit to work with :D