Me blindé literally means “I armored myself,” from blindar, to shield or protect with armor. In the song, it is used metaphorically to describe becoming emotionally guarded after experiencing betrayal, danger, and hardship, making it a striking and memorable expression.
Daniel Castro raps from inside a life he says he picked because "nunca vi otra salida" (I never saw another way out). The verses list what that life costs: post-traumatic stress, no one to trust, a jail sentence landing "en mi mejor momento" (at my best moment), teenage gunmen, and a line that turns a proverb into a rule: "Maldito sea el hombre que confía en otro hombre" (cursed be the man who trusts another man).
The hook is the title. "Me blindé" (I armored up) is both literal, a bulletproof vest in a street at war, and emotional, a man who stopped smiling. His way of coping is spelled out with no apology: reggae and weed to calm the vibe. Near the end he admits the contradiction in his own career: a pastor told him he had talent, "pero le canto al sicario" (but I sing to the hitman), and he regrets it. Eiby closes the track shouting out Panama and Costa Rica, the two scenes the collaboration bridges.