I'm more curious if he was actually studying. A lot of people claim they can study for these absurd amounts of time when the vast majority of it is actually spent staring at a page or even rereading the same page.
Marty Lobdell did a fantastic talk a while back [1] that changed the way I used to study and I'd recommend it to anyone who feels like they aren't studying efficiently.
[1] https://www.youtube.com/watch?v=IlU-zDU6aQ0
