In Cormac McCarthy's novel "The Crossing," the concept of doomed enterprises highlights how certain events or decisions can irrevocably alter the course of a person's life. Characters find themselves marked by their past, creating a stark division between their former selves and who they become after significant trials. This reflects the idea that choices often lead to irreversible consequences.

The quote emphasizes the lasting impact of these pivotal experiences, suggesting that they create boundaries in one's existence between what was and what is. As individuals navigate through life's challenges, they must confront the reality that some paths taken can forever change their identity and perspective.