One should try to purchase a ticket to go back home, back to Godhead. The price of such a ticket is one's intense desire for it, which is not easily awakened, even if one continually performs pious activities for thousands of lives. All mundane relationships are sure to be broken in the course of time but once one establishes a relationship with the Supreme Personality of Godhead in a particular rasa, it is never to be broken, even after the annihilation of the material world. — Sri Caitanya Caritamrita, Adi Lila, Chapter 01, Text 56.
The desire to gratify one's own senses is kama (lust), but the desire to please the senses of Lord Krishna is prema(love).
Desire is most powerful and subtle. Due to desire people become president , go to jail, marry or divorce. Due to desire everything that is happening is happening in this world with Krishna's sanctioning because everybody is desiring imperfectly no one is satisfied and the more there is uncontrolled material undirected desire the is the chaos. The passport to get out of this material world is pure desire which can be cultivated.
A devotee's only desire is to please Krishna and nothing else but Krishna's pleasure. Hence Krishna, in order to please his devotees, shows his pleasure.
By hearing from the Guru, we can understand what is the desire of Lord within our heart.
Disciplining the mind is not a question if whether there are unnecessary desires or not. It is a question of how you are willing to control your desires