Welcome aboard, Stefano! Nice to see another language adict here
(that was meant as a compliment).
My dad once knew a girl from Europe that could speak 7 or 8 fluent languages, and was then working on the Chinese language (I always forget what it is called!) to add another to the list. She could switch her thoughts back in forth so she would actually THINK in that language. That is the goal, though. I hope that I can accomplish that with German.
BTW, Stefano, why isn't German on your list?