“Krs” means “the cause of existence” and “na” means “cause of bliss.” Because of this, he is the supreme form of God. “Cause of existence” sounds good for philosophers, but what does it mean for the devotees of Krsna? For the devotee, everything is in terms of love for Krsna. Their very lives depend on him.

O lotus-eyed Lord, whenever You go away to Mathura, Vrindavana or Hastinapura to meet Your friends and relatives, every moment of Your absence seems like a million years. O infallible one, at that time our eyes become useless, as if bereft of sun. SB 1.11.9