This hankering after perfection is seen in even the most perfect devotees. So we should never think of being perfect at any stage. Actually, Krishna Consciousness is unlimited, because Krishna is unlimited, so we do not know at which point the perfection is there. Even Krishna Himself thinks that he is imperfect to understand Radharani's feelings of devotion; and to understand the devotional feelings of Radharani, He became Lord Caitanya, to worship Krishna in the feelings of Radharani.