I'm very late to the party, but I thought this was a fun question to answer. If I were a Rithmatist, I would spend my time wondering why the Master chose me. I passed all my math classes in school but retained very little, and I'm not naturally math-brained. I also can't sketch anything more complicated than a star. I wouldn't be very good at lines or at chalklings, and my battle reactions are subpar at best, if my experience with Overwatch is any indication. Do you think there would be Rithmatists at Nebrask like me? If aptitude at math, sketching, and thinking quickly are what make a good Rithmatist, but if Rithmatists are chosen at age 8 (before these characteristics would necessarily be evident), then clearly Rithmatists are chosen based on other criteria. This forum speculates on the question of "other criteria" at length, so I won't go into it, but it does make me think that there would be some Rithmatists at Nebrask who only survive because of their intense training, not because they're naturally talented at any of the components. I'd like to meet someone like that in book 2!