1) The author proposes learning _everything_ under the sun, so that one has enough dependencies to learn new topics. This is like downloading most of the packages in aptitude to speed up builds.
However, I prefer to go about it in a different way. I focus on patience and normalizing myself to long and deep build chains. Learning a light topic in a new domain can take hours, if not days, to understand it deep enough to successfully use it to learn other concepts.
When there is something I need or want to know, but when I pull up Wikipedia and see a bunch of foreign vocabulary, I will create a dependency list of vocabulary, and learn everything I need to know to read that article and flawlessly understand it. If it is a new topic it can sometimes take a week of slow learning to quickly learn. It seems painfully slow, but it's learning a large chunk of a new domain in a week. This could be something a college class takes months to go over, so the rate is quite accelerated even if at the time it doesn't seem like it. Slow and steady really does win the race.
2) >I keep trying while following a breadth-first-search approach to domains and resources as described above.
and
>Stop. This is counter-intuitive, but unless you want to become a master at something (besides learning), you really just want to know everything at an intermediate level.
When recursively learning prerequisite concepts, usually understanding 100% of every prerequisite concept is necessary. There are no short cuts. In this scenario a depth first search is ideal, finding the root and starting there.
Likewise, a dependency chain of concepts is a chain of abstraction. When learning a prerequisite concept, no matter how abstract it is, it must be thought of as concrete. It must be understood as if it is concrete. This is the minimum bar to using a concept to build up other concepts. This is can be thought of as an intermediate level of understanding, but I suspect for most people this means mastery. Don't stop short.
3) What is learned will be forgotten within a couple of weeks, unless it a) has been pondered about a minimum of 6 seconds, usually by making up a story to describe it to yourself. The 6 second rule is a neurological limitation that is required to move the memory from short term to long term storage. And b) It is strongly beneficial for what is learned to leave the mind and come back into it on one way or another. This can happen by doing something with your hands, talking out loud about it to someone else, or note taking. This is important and without it details will be lost. I write in a condensed mind-map list like format for this reason. Likewise if I forget something or remember something wrong, I can go back with a ctrl+f and figure out what I did wrong.
4) Etymology is massively important when it comes to learning. The history of why the concept is called what it is called, as well as understanding why it was invented or how it was discovered. I try to visualize what the world was like before the thing I am learning existed and how things used to be done. This teaches me of it's power and when and why to use it. When etymology is done right, the mind will record the concept into spacial awareness which is the strongest and longest lasting kind of memory we have.
There is a lot I could say, but by understanding where people are coming from, you can apply what technique is ideal for that specific task. Learning is no different. One can master it, and from that the gains are innumerable.