Navigli refers to the system of canals in Milan, Italy. It's a specific geographical and cultural reference that might be unfamiliar to learners outside of Italy.
In the song, Mengoni sings, "Sono fuori lontano dai Navigli come / Partire e andare in India per cercarsi altrove" (I'm far away from the Navigli like / Leaving and going to India to find oneself elsewhere). This line uses the Navigli as a symbol of home or a familiar place, emphasizing the protagonist's desire to escape and find himself far away, making it an evocative and unique word choice.
"Migliore Di Me" is Marco Mengoni watching a relationship end without a fight. He tells his ex he has nothing to say, but the calm is a lie: underneath he feels numb, then wrecked, unsure whether he ever really trusted himself enough to be loved.
The song moves between escape and confession. He imagines running off to India, driving too fast, disappearing for days, but keeps circling back to the same admission: he isn't good at explaining himself, and he'd rather start a small war than say he still misses her.
By the chorus he stops blaming her entirely. He is his own biggest enemy, and she, he admits, comes out of it better than he does.