I observe a group of senior citizens regularly assembling in the early hours to twist and turn. They do so in hopes of staying fit.
A person gets old. Yet the same spirit soul still inhabits his body. The spirit soul is eternal. It never undergoes any change. The body on the other hand is always subject to change. Desires nevertheless persist along with the soul.
These people still want to run. They still want to travel to their favorite places. They still want to eat all their fancy dishes.
But the body has slowly voiced its non co-operation. Everyone experiences this phenomenon. We have to learn the difference between spirit and matter. The Bhagavad-gita informs nasato vidyate bhavo nabhavo vidyate satah: “… of the nonexistent (the material body) there is no endurance and of the eternal (the soul) there is no change”
The more we learn to lead our lives agreeing by this principle, the more we will not be disturbed and affected by the inevitable changes of our bodies.