Pedazos literally translates to "pieces". While it might seem like a common word, its usage in this song is particularly poignant and metaphorical.
In the lyrics, the singer, heartbroken and feeling discarded, tells his former love, "Junta pedazos de mí / Donde los hayes tirados" (Gather pieces of me / Where you find them thrown). This imagery of his soul or being shattered into pieces and scattered around makes the word incredibly impactful and memorable in the context of the song's theme of loss and despair.
This song is pure heartbreak drama in the most direct way possible. Remmy is talking to someone who has walked away from him and from everything they shared. He feels like she doesn’t care at all about what he feels: “Tú renuncias a mis besos” [You give up my kisses] and “No te importa lo que siento” [You don’t care about what I feel]. For him, forgetting her is almost impossible: “Es difícil que te olvide” [It’s hard for me to forget you], and trying to make her understand his pain is useless: “Es inútil que me entiendas” [It’s useless for you to understand me]. He even says it’s “más fácil que yo muera” [easier for me to die] than to keep living like this, which is dramatic, intense, and very on-brand for a hurt love song.
What makes the lyrics stick is that he doesn’t just say he is sad. He talks about losing hope completely: “Es preferible morir cuando ya no hay esperanza” [It’s preferable to die when there is no hope anymore], and “Ya me perdiste la fe, ya destrozaste mi alma” [You already made me lose faith, you already destroyed my soul]. The strongest image is in the chorus: if she ever wants to feel those good moments again, she will have to “junta pedazos de mí donde los halles tirados” [gather pieces of me wherever you find them thrown around]. It’s like he’s saying that after this breakup, he is shattered all over the place. The song is one long emotional monologue from a guy who feels destroyed, talks in extremes, and still leaves the door open a tiny bit, but only if she’s willing to pick up the broken pieces of who he used to be.