Imagine the storyteller as a wave that keeps rolling toward a mysterious lover on the shore. Each surge of water brings him closer, yet every sunset snatches her away again, pulling him back into the deep. He spends his nights diving through memories "in the fondo del mar" and his days combing the sand, convinced that if he can just build the perfect castillo de arena (sandcastle) under her feet, she will appear.
The song paints a bittersweet picture of summer love - beautiful, fleeting, and stubbornly hopeful. The beach becomes a stage where tides represent longing, the moon signals loss, and a humble sandcastle stands for faith. Even when the season ends and others abandon the shore, the singer vows that searching, listening, and dreaming of her is still "worth it." It is a gentle reminder that some feelings are as temporary as summer, yet as powerful as the sea.