The whole mind is giving whole attention to all of the parts of universes and this dissolves the universe in form of an ecstasy, bliss and joy beyond words–“Ananda–which is lord Narayana—-Shri Mahavishnu. Buddha-the-Gautama and Zen do pay attention on “whole mind,” which is to attend the universe(Narayana) and remember it all the time.
The totality of attention is the basis of Siddhi or Mahasamadhi by meditation; meditation be it of witness sense(expressed as in ‘watching the ‘thinker’) or be it pure imagination with sustained attention. The method of meditation suggested in Bhagvata Purana is to first imagine any one part of lord Mahavishnu and then another in a series of isolated events and then imagine them together. The stories which play a great role in entering into the subconscious of a Sadhaka are very important because they lay down the foundation on which crops of Bhakti are cultivated to give Amrita-rasa of infinite bliss called ‘Shrihari.’
Moon represents whole mind and Buddha was born on a full Moon day. Krishna was not born on a full Moon day but his beautiful face was Moon like; he was born at midnight. Many saints like Kripalujimaharaj, Guru Nanaka(Sikhism), and others were also born on a full Moon day. Full Moon suggests a consciousness which is subtle, sensitive and soft and which is waiting to bloom fully.
The Bhakti, greatest of yogas without any doubt has been a great whole mind concept. The attention when sustained, gives rise to totality of energy which is directed at making universe blissful, because this attention starts vibrating your consciousness at such a high frequency that you are able to be blissful at every given moment. Bhakti is therefore a metaphysical practice. The monkey mind is the source of all trouble, that is why you need to put your attention to a sense object which is full of goodness–sattva–pure creative energy and beyond–because when you give your attention to any sense object without being careful about its goodness, you would end up being less alive and more trapped in Karmic debt. That makes Bhakti a practice where a Sadhaka(practitioner) chooses his goal in form of bliss–the anand in search of which entire universe is moving randomly and with causes.