We are not impersonalists, under the circumstances we have got varieties of perception in the matter of discharging devotional service. In Rupa Goswami's "Siksamrta'' it is stated that advanced life in Krsna Consciousness means one should be always very much anxious to calculate whether every moment of his life has not been utilized in devotional service. This is called feeling of being afraid for misusing time. One should be very careful to estimate how every moment of his life is being utilized in the service of the Lord. The Goswamis were very much advanced in this line of action, and therefore about them it is said "nidra hara bihara vijito'' that means one who has conquered over eating, sleeping, and mating.
Letter to Yamuna, 2 March, 1970