There has been a rumor in the world since ancient times, "Give a man a carefree and worry-free girl, and he will have three years of life in exchange for a worry-free life."
Forgetting and recalling may be just a joke of time in people's eyes, but no one knows that they have control over it. Forgetting and remembering are both their own choices.
As time goes by, the carefree girl wanders around the world, unchanged for thousands of years, immortal for ten thousand years, taking three years of life to be forgotten and remembered by others.
A worry-free girl is not worry-free. Three years after another, when do you remember and when do you stop?