Even if you can remember all the sermons spoken by the Buddha over his forty-nine years of teaching, and do not misunderstand a single doctrine of the three and five vehicles of liberation, if you do not greatly awaken once, you cannot be acknowledged as a true Zen adept. So even if you can expound a thousand scriptures and ten thousand treatises, cause the Buddhas to shed their light, cause the earth to tremble and the sky to shower flowers, this is just the understanding of a professor, not that of a real Zen adept.