There are numerous times where I've read a lot of material quickly, not really mastering it but making a mental note of where to find that later. It's easy enough to go back and look up facts, reference material, or techniques for solving a particular kind of problem later, you don't need that to change your life.
Another other problem is: it's hard to know what books will change your life. For me, Fermat's Enigma (https://www.amazon.com/Fermats-Enigma-Greatest-Mathematical-...) and The Last Lecture (https://www.amazon.com/Last-Lecture-Randy-Pausch/dp/14013232...) were both life changers, but it would have been hard to know that going in to reading them.
Still another problem is that there are multiple ways at getting repetition. One approach is to read one book really intently. Another approach though is to consume similar related media over a period of time. If you listen to a weekly podcast (like EconTalk, for one example), very often similar themes come up over and over again. Or you can read several books by one author, or a group of related authors.
Finally, and maybe this is a more minor point, the post's author mentions taking down great quotes. One thing I've realized from my reading is that great quotes sometimes help summarize and understand the flow, but pretty often they don't. One of the nice thing about reading on the Kindle app on a phone is that there are multiple colors for highlighting, and I find it helps to highlight differently for "this is an awesome quote" vs. "this sentence is important in following the structure of the argument."