Please explain the poem: "People traveling from south to north grow old, and the setting sun sends fishing boats home."

Describes a state of tranquility and leisure that a person enters after experiencing a lifetime of ups and downs and ups and downs. It reflects the poet's indifference to fame and fortune and his pursuit of returning to nature.

Source: "Hanjiang" by Du Mu of the Tang Dynasty

I understand it myself, so answer it seriously and give a satisfactory answer, thank you