Rompecabezas is a fun Spanish word that literally means "head-breaker" (from romper - to break, and cabezas - heads). It's the common word used for a "jigsaw puzzle".
In this song, Ricky Martin uses it as a powerful metaphor for his life, singing "Le faltan piezas al rompecabezas" (The puzzle is missing pieces). He's expressing that his life feels incomplete and doesn't make sense without the person he loves, creating a vivid image of heartbreak.
This song is a classic breakup ballad from Puerto Rican superstar Ricky Martin. It's all about that awful feeling when you're trying to move on, but you just can't. He lays it all out, starting with a specific count: "Van diez noches sin hablar" (It's been ten nights without talking). The days are a mix of ups and downs, as he says in the title line, "A veces bien / Y a veces mal" (Sometimes good / And sometimes bad).
He's completely stuck in the past, admitting how hard it is to forget someone you loved so easily. The song uses a great image for this feeling of being incomplete: "Le faltan piezas al rompecabezas" (The puzzle is missing pieces). He's surrounded by memories, even saying the photos on his table feel heavy. In the end, he's just hoping the other person feels the same way, asking them to please tell him "que nuestro amor no murió" (that our love didn't die).