From my experience, the trick to memorizing 10,000+ questions and answers at the 90% accuracy level was to read and perform hands-on practice on all questions the first time (took about 10-hour per day x 6 days x 19 weeks). Then, at the second time, I marked any questions that were recalled inaccurately. Third time, I only read the marked questions and reiterated until all the last batch could be recalled at 100% accuracy. On the test day, I would still miss some items and be surprised by a few more. I might have to retake the test more than once to pass at the scores of 85%+.
 
The trick is to trigger my brain to pay attention to only mistakes, not everything (please only apply this in the context of studying for a test, and maybe playing detective with a stack of 1000-page books). It’s easy to do because we humans are natural at learning from mistakes. This is how proper planning can beat a genius.