Yeah I agree this is an important idea. I would suggest a couple tests for whether your knowledge is sufficiently connected in way that Musk advocates:
- (if you went to college) Did you have moments when the different courses connected? I think when people are poorly educated in college, it's because of this unfortunately common experience: they learn a bunch of specialized and disconnected subjects, never relate them to anything in their lives, and then forget them all.
I remember the subjects in CS/Math/EE starting to connect more and more around junior year, and I liked that feeling of a light bulb going on. You have to make a bit of extra effort. I did some little experiments outside class. I remember writing Matlab program (an "engineering" tool) to do some experiments in non-Euclidean geometry (pure math).
Of course there are some subjects that never connected, and I forgot those things.
When you have that semantic network, it lets you evaluate new ideas and designs more quickly. You see which low level principles come into play from the high level variables.
- (if you are a programmer) I think there's a pretty clear "semantic tree" in computing: from computer architecture, to OS, to programming language, etc.
So the test is: If you are generally satisfied with how computers/phones/etc. work, then I would humbly suggest that your semantic tree of computers isn't very well fleshed out :) I think any good programmer should see lots of areas where the status quo is just a result of path dependence and not actual any design principle.
When you have a good knowledge of all levels of the stack, then you can be creative. For example, I'm looking at Xen right now, and it has dawned on me that paravirtualization is a great idea (or perhaps great hack).
The related Mirage OS / unikernel line of research is another great example of connecting all the dots, and coloring outside the normal lines. 99% of programming jobs are basically coloring within the lines, where it doesn't matter if you have developed this semantic tree or not.
Somewhat related: there were some recent threads about organizing personal information, and I wrote about using a Wiki: https://news.ycombinator.com/item?id=8753599
Some people talked about using a journal to record thoughts or knowledge, but my point was that hyperlinks literally model the relationships in your head, and thus are superior for information organization / recall.