More than a few times i would re-read the textbook end to end in the week leading up to final exam. Particularly for subjects that I knew were foundational for future courses. 20 years later I still find myself breaking out my old textbooks several times a year to refresh a topic. I’m referring to mostly engineering, economics, and finance textbooks. As much as I enjoyed philosophy and ethics, I don’t find myself needing to break those books open.