how does the night makes us forget about our pain and sorrow

From the text:

Sometimes, our pain is very deep and real, and we stand before her very silent, because there is no language for our pain, only a moan.  Night’s heart is full of pity for us: she cannot ease our aching; she takes our hand in hers, and the little world grows very small and very far away beneath us, and, borne on her dark wings, we pass for a moment into a mightier Presence than her own, and in the wondrous light of that great Presence, all human life lies like a book before us, and we know that Pain and Sorrow are but the angels of God.