intelligence department!!!

subtlety in definition of "mere note-book" versus card index

Kaiser doesn't give a strong definition of the difference between notes (here taking on a fleeting sort of definition), and notes indexed and arranged, but he gives it a powerful sounding name and implies that there is useful power within the practice of doing so.

I like that she's explicit about not migrating over all of one's highlights and annotations after the fact. Few people focus on this piece which is highly important and many beginners fall trap to thinking that they need to write down, save, and link everything.

What if the initial exercise of making the fleeting note was enough to have a baseline knowledge of a thing that really isn't going to be used again? Save the time and effort for the really important ideas. Build these.

An annotation like 2+2=4 is useful in 2nd grade and will be remembered/used for your lifetime. It's so ubiquitously commonplace that it doesn't need to be commonplaced into your zettelkasten. Similarly for basic ideas that anyone in a particular sub-field will already know. Delve deeper for building true insights.

This is related to the idea of collector's fallacy, but is subtly different from the usual framing. It has to do with focus against the commonplace.