Incognita translates literally to "unknown" or "an unknown quantity," like the 'x' in a math equation. It's a more formal and evocative word than the more common sconosciuto (unknown).
In the song, the singer acknowledges that the future is una grande incognita ("a great unknown"). He uses this sophisticated word to beautifully express life's uncertainty while promising that his love is strong enough to face it.
Sal Da Vinci goes all in on wedding romance with "Per Sempre Sì", turning a real-life walk down the aisle into an unapologetic pop anthem. He starts at the very beginning when he was just an unknown stranger to her, before watching her transform into "una regina ora vestita in bianco sposa" (a queen now dressed as a bride). The track does not pretend romance is effortless, either. He flatly insists that love is not lifelong love "se non ha affrontato la più ripida salita" (if it hasn't faced the steepest climb), framing their shared dream of kids in a big house as something earned through real struggle.
What makes the song feel so alive is how practical and grounded he keeps his big promises. Looking ahead to the unknown future, he vows they will build everything together without raising walls, offering a totally honest shrug about married life: "Litigare e far l'amore poi che male c'è" (Arguing and making love, what's so bad about that?). Right before the final chorus, he swears his vow with his hand on his heart before God, shifting smoothly into his native Neapolitan dialect with "Accussì / Sarrà pe sempe sì" (Like this / It will be forever yes). It packs eternity into one simple word, proving that genuine devotion does not need to overcomplicate things.