This idiom advises against worrying about future problems until they actually arise, advocating a focus on the present rather than speculative concerns. It suggests dealing with challenges only when they become imminent, much like crossing a bridge when you reach it. The phrase is used to promote pragmatism and reduce anxiety in planning, decision-making, or stressful situations, often with a reassuring or dismissive tone.

The phrase likely emerged in 19th-century English, rooted in the literal act of crossing bridges, which were often obstacles in travel due to rivers or poor construction. An early use appears in Henry Wadsworth Longfellow’s 1845 poem *The Golden Legend*, where a character says, ‘We’ll cross that bridge when we come to it.’ The proverb reflects rural life’s practical wisdom, gaining traction in the Victorian era as a metaphor for deferred worry. By the 20th century, it was common in American and British English, appearing in Mark Twain’s writings and later in self-help literature, emphasizing mindfulness and strategic timing.