Based on Bhagavad Gita Chapter 06, Text 21
Attention is crucial for enjoying anything. When a reputed sports player is in action, fans enjoy by attentively watching all the action and even the replays.
We need attention to relish devotional life too. While performing spiritual activities, we experience devotional happiness only when we become internally attentive to the presence of Krishna.
Otherwise, if we are inattentive in, say, our daily meditation, we soon find the meditation sessions uninspiring and uninteresting. At such times, attention feels like detention. The Gita injunction to be attentive seems like a deprivation of our mental freedom to think of more enjoyable things.
But the same Bhagavad-gita (6.21: sukham atyantikam) declares that the spiritual platform offers the ultimate happiness. Why don’t we experience this happiness?
Because of misdirection of desires caused by deficient conviction.