One may embrace and become more dedicated to a note taking practice after realizing how much useful information would've been lost had they not jotted down some

One may embrace and become more dedicated to a note taking practice after realizing how much useful information would've been lost had they not jotted down some notes. It stems from a deeper acknowledgment of the limitations of the mind and the practicality of the pencil. Taking your question from the reverse perspective, we can say that one does not take notes for at least one of two reasons, either because they think they can afford to forget the information they've already spent time to acquire, or they trust their mind to recall enough of it when they'll need to.