[marginalia_nu]

I think the contrast should be between studying and internalizing a subject versus having the ability to look up a subject. That seems the most true to Plato's intention.

It's common and easy to fall into considering the things you could look up as things you already know.

What's the difference, one might ask? What's the problem with offloading some of this knowledge and free up space in your head? Well the thing when you learn something is that it doesn't just permit access to the information, it also permits synthesis of new ideas. The sum of knowledge is greater than its parts.

A very concrete example: As someone who only speaks English one may look up the Latin terms 'manus' (hand) and 'facere' (to act/do/make); but unless you actually do, you'll probably not immediately grok the etymology of the English term 'manufacture'.

[_glass]

Exactly. My compsci prof was forcing us to learn so much by heart, but then it's internalized and you start to think in those terms. Right now I am writing my PhD thesis in management and in the beginning I didn't have all of those papers really in my head. But now slowly that knowledge accumulates and I can think through things I couldn't think before. But on the other hand, I now think, how could I not understand that, it's trivial. And to add, it is the same for literature and poems. If you know a poem by heart, it's not just fancy to recite it, but that you start to really incorporate part of that language.

[ethbr0]

I think of it in terms of computer memory levels.

There are some computations (synthesis) that require so many (non-front loadable) memory accesses that it's impractical to do them from memory with significant delay (books), because the number_of_accesses * access_time dominates the project time.

Instead, you must have a working set of core information (or at least pointers to information) in low-latency memory (your brain).

Example: How much longer would it take me to do a multi-digit multiplication if I had to look up the process for multiplication in a book for every digit multiplication I did? And what if that multiplication were just one of many in the higher-level math problem I was trying to solve? (Then generalize to any problem that requires a core base of knowledge)

[kristianbrigman]

It is very similar to caching performance impacts. And like you say, sometimes performance is just faster, and sometimes it actually enables functionality…