Derrumba comes from the verb derrumbar, meaning to knock down, demolish, or crumble. It's a strong and evocative word that goes beyond simple sadness.
In the song, the lyric "Pensar en verte me derrumba" (Thinking of seeing you knocks me down/crumbles me) powerfully conveys the emotional devastation the singer feels at the thought of encountering their ex. It paints a vivid picture of being completely overwhelmed and broken by the memory or potential sight of a past love.
"La Mitad" is about the ache of a breakup that still feels unfinished. The singer describes home as half empty now: a half-drunk glass, a half-made bed, a table set for two that isn't needed anymore.
The chorus is the heart of the song: their ex took half of them when they left, and that missing half is the singer's punishment. Even simple pleasures like going out with friends feel wrong now, because every quiet moment brings the same questions back.
The hardest part is watching an ex move on and be happy with someone else, while the singer keeps wishing they could turn back time and give the relationship one more chance.