This is a fun exercise, then ask the second question "How productive can I be in my job when the network is unavailable?" The author states : What I’m trying to show with all this is that you can do something 100 times but still not remember how to do it off the top of your head. My experience differs from this, if I were to rewrite it I would say something like: "You can do something 100 times, and as long as you ca…
nautil.us/issue/40/learning/how-i-rewired-my-brain-to-become-fluent-in-math-rp
Or Feynman on the need for mathematical fluency to do physics:
> What we have to do is to learn to differentiate like we know how much is 3 and 5, or how much is 5 times 7, because that kind of work is involved so often that it’s good not to be confounded by it. When you write something down, you should be able to immediately differentiate it without even thinking about it, and without making any mistakes. You’ll find you need to do this operation all the time—not only in physics, but in all the sciences. Therefore differentiation is like the arithmetic you had to learn before you could learn algebra.
> Incidentally, the same goes for algebra: there’s a lot of algebra. We are assuming that you can do algebra in your sleep, upside down, without making a mistake. We know it isn’t true, so you should also practice algebra: write yourself a lot of expressions, practice them, and don’t make any errors.
Of course, in this particular discussion re: javascript, I think the design of the language doesn't help much here. Consider Javascript's `Date`, which the OP calls out as an API with a particularly difficult to remember set of conventions. Authors of languages and libraries can remedy this by having a coherence in design, naming, and behavior that help people build mental structures to memorize how these work and achieve the kind of fluency they need to do things without googling. Ruby's standard library I think is particularly good at this(here "principle of least surprise" helps not just with discovery, but retention).
EDIT: also want to add that using documentation and external resources is totally valid, as the grandparent comment states. There's just a balance to be had between relying on Google versus what you can draw from your mind quickly. Also think it's worthwhile to note that there is interesting work to be done in making documentation systems better and more integrated into our runtimes, see for example: https://www.geoffreylitt.com/margin-notes/