You have aged. Your energy level and motivation will decline until you die.
The rate of change varies from person to person, and you can probably reinvigorate yourself to a degree with a better lifestyle (more exercise, a better diet, a stimulating job, a vibrant social life), but slowing down is inevitable.
The rate of change varies from person to person, and you can probably reinvigorate yourself to a degree with a better lifestyle (more exercise, a better diet, a stimulating job, a vibrant social life), but slowing down is inevitable.