The prodigal son never changes his gold. Synonyms: the loser never changes his gold, turns his back and turns over a new leaf.
Interpretation:
"The prodigal son will never change his gold" is from "The Eighty-first Dream, the 32nd Dream" by Zhang Henshui, a master of modern literature. It is also a famous saying used to compare some young men and women who have lost their lives in society to turn over a new leaf and repent.