Because a run going for a 1 CC isn ' t practice , it ' s a test . If you get a 1 CC it ' s proof that you master the game to such an extend that you can beat it with every tool available for you and shows a mastery in those tools . Much like in a real life test it doesn ' t make much sense to try taking the test as much as you possibly can until you pass . Sure , after hundreds of tries you might finally pass that danged test . However it ' s way easier and less time consuming to just learn the parts that you have trouble with . Why bother redoing the whole test and needing to solve 53 again even though you have no problem with addition , if the part you fail on is multiplying 53 ? It makes much more sense to spend your time to practice multiplying , where you have trouble with than spend time on something you already can do . Now instead of a test , it ' s a 1 CC . Why would you bother trying to grind out runs where you have to do stage 14 when you find stage 5 extremely difficult ? Why would you fight a whole stage to just get to that one tricky spell that gives you trouble ? It ' s just not worth it . And , unlike real life where mastering multiplication doesn ' t help you with the easier addition , in Touhou knowing how to dodge fast bullets precisely DOES help you with dodging slow bullets precisely . When you start a run for a 1 CC , you should be able to posses the capabilities to 1 CC , you should already know the stages and the amount of attacks you can ' t do should be low . Only then does it make sense to go for your accomplishment !