I've been doing this as well, but I specifically try to come up with good questions and add those. Usually at the time I add the question as a flashcard, I don'

I've been doing this as well, but I specifically try to come up with good questions and add those. Usually at the time I add the question as a flashcard, I don't know the answer yet, so I leave that field blank. Later on every time the flash card shows up, I refine the answer and return to the textbook if necessary. I find that the effort required to come up with interesting questions is very beneficial to the learning process by itself. I also sometimes include the name of the book and page numbers so I can quickly return to the relevant section.