For books I'm trying to learn and retain from, like a textbook or a technical book it really helps me to take notes, underline, highlight, write questions, etc

For books I'm trying to learn and retain from, like a textbook or a technical book it really helps me to take notes, underline, highlight, write questions, etc in the book itself. I think it both helps me retain it better the first time and then allows me to review the text later and get more out of it.