It takes inspiration to be able to chant your rounds every day. Srila Rupa Goswami explains that on the spontaneous platform, the inspiration comes from one's spontaneous attachment to the
service itself. But on the platform of vaidhi bhakti, the inspiration must come from the spiritual master and from the revealed scriptures. My point is that whether out of duty or out of spontaneous love, there must be inspiration in order to engage in devotional service. Your primary duty, therefore, is to draw on your greatest source of inspiration to help you to chant every day. Even if you chant all of your rounds, but just do it begrudgingly, your progress will be hindered. Bhakti cannot be generated mechanically. Bhakti is eternal. It must be awakened by our practice in sadhana bhakti.
(Collected Letters to My Disciples, Vol 3, Pg 44, 3rd Paragraph)