> The rule of thumb I use is to understand something just enough to express what it does without necessarily knowing exactly how it does that. This process is called "chunking," and it relies on the fact that once you have a basic understanding of a unit of code, "you don't need to remember all the little underlying details" (Oakley).
Isn't this how a lot of non-math majors learn math at uni? You learn how to use it, but you don't learn the proofs behind it? When I dove into a first codebase, I took the above said approach because that's how I learned (most) math.
A younger me would've find the Tools section valuable.