In Alice Munro's "The Moons of Jupiter," the quote reflects on the passage of time and its effects on relationships. The idea that time has lessened the brightness of their connection suggests a sense of nostalgia for what once was. It highlights a transformation where the vibrancy and excitement have faded, replaced by a more mundane existence.

This sentiment also emphasizes the notion that challenges and difficulties have played a role in this change. Rather than showcasing growth or improvement, the struggles faced by the characters have led to a deterioration in their bond. Ultimately, Munro portrays the bittersweet reality of how both time and adversity shape human experiences and connections.