Create a Knowledge Database
If there's one thing I learned after reading 300 books, is that information quickly vanishes from the mind. The forgetting curve illustrates this point very well. When you're exposed to new information just one time, it soon gets forgotten. From the graph, 75% of what you learned 6 days ago disappears, if not later reviewed.
Taking notes and later conducting multiple reviews is the best way to interrupt the forgetting curve.
Taking Notes
Starting with the note-taking process, my brain lights up every time it sees a database with notes, like my own. It is, indeed, a positive habit to develop: taking notes on books, articles, videos, conferences, or informal conversations. Unfortunately, I used to take notes in different places — physical notebooks, word documents, google docs, Evernote, and so on. Needless to say, I could never find what I was looking for.
Since I started using Notion that all my notes remain in one place. Notion is a free, easy to use software, that syncs across all of your devices, and allows you to organize different areas of your life in just one platform. Inside Notion I have got a database with all my notes on various forms of media, including online classes. Because every note is searchable and categorized, I can quickly review content and refer to old information. It's like building your own knowledge encyclopedia.
I am currently reading the book "Feminism is for Everybody" and my notes are being structured this way for future reference. I add tags that allow me to filter all the notes and ease the access.
Reviewing Notes
There are different approaches to review the notes you took. For me it all comes down to one question: Do I want to lightly refresh my mind about this particular subject, or do I want this information to stay in my memory?
If I just want to quickly recall what a particular book was about, I will simply re-read the notes I took and perhaps make the effort to remember the 3 most important ideas.
On the other hand, if my intention is to get information into long-term memory, I use active recall to make it happen. If you don't know what active recall is, just read this quick post.