Desapercibida means "unnoticed" or "unperceived." It's a less common, more sophisticated word than simply saying "not seen."
In "Un Hombre Normal," the singer uses this word to express his intention to hide his sadness: "Para que pase desapercibida mi tristeza" (So that my sadness goes unnoticed). It highlights his effort to maintain a facade of normalcy despite his heartbreak, making it a poignant and memorable choice.
Have you ever had to pretend you were okay after a breakup? That's the heart of this classic salsa song by Puerto Rican artist Willie Gonzalez. The singer is facing a tough reality: the person he loves is no longer interested in him. He realizes he was never their "priority" or "center of attention" and now has to accept that he is no longer in their "heart."
Instead of showing his pain, he decides to put on a brave face. He plans to act like a "normal man" who can live without her and doesn't feel bad. His strategy? He's going to smile so his sadness goes unnoticed ("Para que pase desapercibida / Mi tristeza"). He promises to leave with maturity and, for the first time, not to cry. But underneath this strong exterior, he reveals he's still a "crazy dreamer" who lives for her, desperately hoping she might love him again one day.