Imprevisível means "unpredictable." It's a captivating word that perfectly encapsulates the central theme of the song.
The lyrics repeatedly use "como" (like) to describe various natural and cultural phenomena, leading up to the declaration that the arrival of a new love is just as unpredictable. This word is key to understanding the song's message about the unexpected nature of love and life.
"Imprevisível" is about how love arrives without warning, and how that unpredictability is what makes it beautiful.
The verses compare life to things that unfold on their own timeline and can't be forced: a river finding its course, a child growing up, a flower opening, a labyrinth, the stars coming out. Falling in love, the singer says, works the same way.
The chorus is set at Arpoador, a beach in Rio de Janeiro known for its sunset views, and lands on the idea that every day carries the chance of a new love. Nothing about it can be planned or described in advance. It just happens, "imprevisível" (unpredictable), and that's the point.