Some notes will be descriptive, others prescriptive
When learning about new topics, notes are more descriptive. Descriptive notes are a way to gather knowledge from disparate sources, since I won’t always remember where I learned something. Descriptive notes also make my learning more conscious, increasing the likelihood I remember something. That said, my notes should relieve my brain of the responsibility of storing knowledge.
When synthesizing knowledge into new idea, notes are more prescriptive. Often these notes are works of opinion, not consciously attempting to assert facts. Biases should be noted if possible, since exploring idea-paths may blaze trails that will more easily followed in the future, even if better paths exist unexplored. These prescriptive notes may bind descriptive notes and prescriptive notes together into new concepts which may build themselves more naturally into future ideas.
I shouldn’t be afraid to take prescriptive notes, even when learning, since interacting with the material will help make my knowledge more practical.