Oscureció comes from the verb oscurecer, meaning "to darken" or "to grow dark". While it literally refers to the absence of light, it's often used metaphorically.
In this song, Marco Antonio Solís uses it to describe a period of sadness or difficulty, singing "Que un día oscureció" (that one day darkened). It's a poignant way to express how a once bright time became dim, reflecting the emotional journey of remembering a past love.
Have you ever seen something that instantly transported you back in time? In this classic ballad, Mexican superstar Marco Antonio Solís sings about exactly that feeling. After a lonely and difficult period, which he calls a "storm," the singer feels the sun shining again and his ability to love reawakens. This new feeling is immediately focused on a past love, all because of a chance encounter.
The trigger is seeing a couple that he and his ex-lover used to know and laugh with. Seeing that this couple now has children makes him realize just how much time has passed. This sends him into a spiral of thoughts, wondering what happened to his former partner. Did they find true love with someone else? Or do they, like him, secretly hold onto the "faith hidden in the soul" that they might one day reunite and give their love another, better chance?