This proverb is part of Spain's rich tradition of 'refranes'—short, popular sayings that contain wisdom passed down through generations. Its exact origin is unknown, as it evolved organically in oral culture. These proverbs were so integral to Spanish life that they feature heavily in classic literature, like Cervantes' 'Don Quijote', to represent the common sense of the people.

This saying reflects a pragmatic and realistic worldview common in Spanish culture. It's a verbal shrug, a way to accept that conflict and differing opinions are a natural part of life. It’s frequently used to end a discussion about a controversial topic, justify a necessary but unpopular decision, or to console someone trying too hard to be a people-pleaser.

The power of this proverb lies in its simple, universal metaphor. Rain ('lluvia') is a natural event that is neither inherently good nor bad; its value depends entirely on your perspective. For a farmer in a drought, rain is a blessing. For someone planning an outdoor wedding, it's a disaster. This brilliant metaphor perfectly captures the idea that the impact of any event is subjective.