Desconocí comes from the verb desconocer, meaning "to not know" or "to fail to recognize." It's a less common word than no saber (to not know) and carries a stronger sense of unfamiliarity or estrangement.
In the song, the artist sings, "Yo recuerdo cuando te conocí / Pero hace rato te desconocí" (I remember when I met you / But a while ago I unrecognized you). This powerful contrast highlights a profound shift in the relationship, where the person she once knew has become a stranger, making desconocí a very impactful and memorable word.
In "Tenía Que Llegar" (It Had to Arrive), Kenia OS is totally over a relationship that's gone sour. She's reached her breaking point and is ready to confront her partner, singing, "De ti ya me estoy cansando / Hoy es el día en que tú y yo hablamos" (I'm already getting tired of you / Today is the day you and I talk). It's clear she feels her partner has changed, asking, "Tú no eras así / Dime porque eres así / Porque me haces esto a mí" (You weren't like this / Tell me why you are like this / Why do you do this to me?).
She's been avoiding this conversation, but it's finally time to face the music. Kenia OS is done with the games and makes it clear that her partner's attempts to hurt her won't work: "Me querías dañar / Déjame decirte que conmigo / No te va a funcionar" (You wanted to hurt me / Let me tell you that with me / It's not going to work). She remembers a happier time, but now feels like she doesn't even know this person anymore. This song is all about standing up for yourself and saying enough is enough!