The quote encapsulates a profound understanding of loss and finality. It suggests that once something has disappeared from our lives, whether a person, opportunity, or moment, it is permanently lost. This reality can be difficult to accept, as we often cling to the hope that we can regain what has vanished. The lesson is stark: accepting loss is part of the human experience, and it teaches us to value what we have while it lasts.

Cormac McCarthy, in "Cities of the Plain," emphasizes this inevitability, reflecting on the transient nature of existence. The statement resonates deeply with themes of mortality and the permanence of change. It serves as a reminder that while we may yearn for the past, we must learn to navigate our present without the certainty of reclaiming what once was.