Jīngguò duōnián yánjiū, tā duì zhè mén xuéwen yǐjīng rónghuì-guàntōng.
After years of research he has a fully integrated mastery of the subject.
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From 《朱子全书·学三》: Zhu Xi (Neo-Confucian philosopher) writes that only after long, deep effort can a learner 融会贯通 - melt the parts together and pierce through them. It's the payoff after prolonged rote study, not a shortcut around it.