During the Western Han Dynasty, Liu An, the Prince of Huainan, was obsessed with seeking immortality and the secrets of eternal life.
One day, eight white-haired elders came to seek an audience with Liu An, claiming they knew the secrets of immortality and wished to serve him.
The gatekeeper went inside to report to Liu An. Liu An came out, took one look, and said, "You yourselves are already decrepit with age—how could you possibly understand the art of immortality? You're clearly here to swindle. Guards, drive them all away!"
The eight old men laughed heartily and said, "Your Highness thinks we are too old and doesn't believe we possess the art of immortality. How about we instantly turn from old to young?" Liu An replied, "Excellent! If you can turn from old to young, we will take you as our masters."
Eight old men murmured incantations, shook themselves, and in an instant transformed into eight children.
Liu An was utterly convinced. He respectfully invited them into his princely mansion to learn the art of immortality, and eventually, he himself became an immortal.
Of course, this story is merely a myth. According to historical records, Liu An, the Prince of Huainan, was later executed for his involvement in a rebellion and never achieved immortality.
Later, the idiom "returning to youth in old age" came to describe elderly people regaining their vitality.
Source: *Biographies of Immortals*
Meaning of the Idiom: Later, the Chinese idiom "返老还童" came to describe elderly people regaining their vitality.