In "Trains and Lovers," Alexander McCall Smith reflects on humanity's impact on the planet, suggesting that while our alterations to the environment may not last forever, their traces can endure. The mounds mentioned in the quote symbolize the lasting evidence of our actions, emphasizing a contrast between the impermanence of change and the permanence of its marks.

This observation invites readers to consider the consequences of their endeavors, both on the earth and on future generations. It serves as a reminder that our influence, even if it is fleeting, can leave a significant and lasting imprint on the world around us.