This relishing of transcendental mellow in discharging devotional service cannot be experienced by all classes of men, because this sweet loving mood is developed only from one's previous life's activities or by the association of unalloyed devotees. As explained above, association with pure devotees is the beginning of faith in devotional service. Only by developing such faith in the association of a pure devotee, or by having in one's previous life executed devotional activities, can one actually relish the mellow of devotional service. In other words, this transcendental bliss is not to be enjoyed by any common man unless he is so extraordinarily fortunate as to be in association with devotees or to be continuing his previous birth's devotional activities.
The gradual process of development to the stage of devotional service is explained in Śrīmad-Bhāgavatam, First Canto: "The beginning is to hear about Lord Kṛṣṇa in the association of devotees who have themselves cleansed their hearts by association. Hearing about the transcendental activities of the Lord will result in one's feeling transcendental bliss always." It is also explained in Bhagavad-gītā that for one who has actually come to the spiritual platform, the first symptom visible will be that he is always joyful. This joyous life is attained by one's reaction to reading Bhagavad-gītā or Śrīmad-Bhāgavatam, or else from associating with persons who are very interested in the spiritual life of Kṛṣṇa consciousness—specifically those who have made the determination to achieve the favor of Govinda by being engaged in transcendental loving service at His lotus feet. Being encouraged by such a feeling, one who is constantly engaged in discharging the regulative principles of devotional service in such a way as to please the Supreme Personality of Godhead develops two principles of compelling force, which come under the heading of vibhāva. Thus one enjoys transcendental bliss.
There are several origins or causes for this compulsive love of Kṛṣṇa, such as Kṛṣṇa Himself, the devotees of Kṛṣṇa, and Kṛṣṇa's playing on the flute. The effect is sometimes loving and sometimes stunted.