I feel I'm too old and tired to be of service. Is there any story in the text that addresses overcoming age-related fatigue and laziness through devotion?

The story of Nanasaheb Nimonkar directly addresses this concern. The text in Chapter 0 highlights that despite being over sixty, Nimonkar was a model of tireless devotion. It is explicitly mentioned that "laziness or a desire for rest never touched him while serving Maharaj." For the last three years of his life, he was constantly and promptly engaged in service, demonstrating that age is not a barrier when the heart is filled with devotion. His example suggests that true service can invigorate a person, overcoming the physical limitations and mental lethargy that might be associated with old age.