According to research, note taking and highlighting are two of the worst ways to study and retain information and has absolutely no value return proportional to the effort whatsoever.
Check out CORNELL METHOD of note taking. Essentially, when you're studying, you want to progressively summarise what you read in your own understanding, create questions which are addressed by what you study - and review those questions and answer them for yourself, comparing
the answer with the written notes/study material. This is a very highly effective method. Just rote highlighting makes you brain think you'll come back to it later, and simply taking notes from a lecture doesn't translate to understanding.
To actually understand something, you have to actually put in time to study the study material, condense each section into summaries in your own words, create exhaustive list of questions that each section would answer, and review those questions twice or thrice in the process.
Done this way, you actually trigger memory recall, and also force your brain to map the questions to relevant answers, and think in terms of application and not in terms of note taking. A lot of videos on youtube explaining this, check it out.
Note taking and highlighting just helps you temporarily store information in your brain for time being - until you're in that act of note-taking. If you want to make knowledge permanent, learning has to become knowing. This process helps.
