If you simply hear and hear in the class of Krsna consciousness, and go outside and forget, oh, that is not nice. That will not make you improve. Then what is? Kirtitavyas ca: “Whatever you are hearing, you should say to others.” That is perfection.Therefore we have established Back to Godhead. The students are allowed, whatever they are hearing, they must be thoughtful and write. Kirtitavyas ca. Not only simply hearing. “Oh, I am hearing for millions of years; still, I cannot understand” — because you do not chant, you do not repeat what you have heard. You have to repeat.
(Jagannatha Deities Installation Srimad-Bhagavatam 1.2.13-14 — San Francisco, March 23, 1967)