It is described that Krishna’s pastimes in Dvaraka are perfect, in Mathura more perfect, and in Vrindavana most perfect. They are most perfect because in Vrindavana the residents engage in spontaneous devotional service. The mood of sweetness, madhurya, predominates and permeates all the relationships in Vrindavana, whereas in Dvaraka and Mathura the devotees serve with an awareness of Krishna’s aishwarya (divine position). Srila Vishwanath Chakravarty Thakura describes that the sweet nature of Krishna’s Vrindavana pastimes is due to the fact that His humanlike activities are never destroyed by the majestic understanding of His opulence. The residents of Vrindavana have no such consciousness. Their level of understanding of Krishna is based on their particular relationship with Him. Their highest realization is that “Krishna is my friend,” “Krishna is my son,” or “Krishna is my lover,” and by these feelings they possess the Lord. Their pure bhakti cannot be disturbed under any circumstances.
(LFD, Vol2, Being Careful to Avoid Anisthita-bhakti, Pg 57, 3rd paragraph)