Demencia translates to 'dementia', but in this song, it's used poetically to mean 'madness' or 'insanity'. It's a powerful and dramatic word that captures the extreme emotional state of the singer.
MANA sings, "Fui cayendo en la demencia con la urgencia de escapar" (I was falling into madness with the urgency to escape). This line vividly illustrates how the toxic relationship felt like a prison, driving him to the brink of losing his mind.
Mexican rock band Maná brings serious drama to this massive breakup anthem. The singer treats a bad relationship like an actual maximum-security facility, shouting right from the start: "Jamás regreso a tu cárcel" (I am never returning to your jail). He admits he let things go too far because he was terrified of being alone: "por miedo a perderte / el silencio me invadió" (out of fear of losing you, silence invaded me). That fear ended up trapping his entire life. Now he is completely done with "las paredes, ni las redes ni el control" (the walls, the nets, nor the control). When he talks about "redes" here, he means literal trapping nets, pointing straight at suffocating behavior where every move gets tracked.
Instead of sulking in a corner, he decides to rescue himself ("Voy a rescatarme"). His escape plan is bold, dramatic, and totally unbothered: "Quiero ahogarme en otros labios / En otro sol, liberación" (I want to drown in other lips, in another sun, liberation). He is not looking for a gentle conversation or closure. He slipped into madness waiting to escape, and now he is walking out the front door and sprinting toward somebody new. It is loud, theatrical, and the ultimate track for when you finally cut someone off for good.