I got lucky, Mother is Greek, Dad is Italian
Now im relatively fluent in English and Greek, my Italian is so-so, but man, i went to Greece when i was like 15 for 2 months, and the amount my Greek improved was insane, i went there speaking very little, came back and could converse fully (to bad its some village dialect, so normal greeks cant understand a quarter of what i'm saying), i could only imagine how fluent i would be if i lived there for >1 year