A man knows when he is growing old because he begins to look like his father.
Márquez catches something more subtle than mere physical resemblance—he's describing the moment when a man recognizes his own mortality mirrored in his father's face, when the generational relay becomes suddenly, viscerally real. The genius lies in treating aging not as a gradual process we notice through mirrors, but as an almost shocking inheritance, a biological inheritance that forces us to see ourselves as *temporary*, as a link between past and future rather than the center of our own story. A man might ignore gray hairs and wrinkles for years until one afternoon he notices his father's exact gesture in his own hands, or catches his reflection at precisely his father's age—and that recognition can either humble or terrify him. This is why the quote moves beyond vanity; it suggests that we don't truly accept our place in time until our bodies betray us with an unwelcome resemblance.