The speaker begins with a small, unflattering picture: a man rubbing his belly, aware that he is getting older and uglier. It's a wry, self-mocking moment, and it sets up a winter of idleness and empty pockets. Being broke isn't dramatic here, just a fact of the cold season.
Then summer arrives and the speaker turns childlike, digging for gold. The title makes him a prospector, but the image feels more like play than serious labor, a hopeful scramble in the dirt after a long, lean stretch.
The ending shifts the tone. The earth is "going to pieces / in my pocket," so whatever he digs up crumbles into dust or soil rather than turning into treasure. The mood is a mix of humor, tenderness and quiet sadness. The speaker keeps chasing something bright, but the poem suggests that what he gathers, perhaps like time itself, can't be held for long.