After watching that interview on the United website, a few thoughts of mine.
1. I'm utterly in love with this guy already, and questioning my sexuality.
2. His English is superb, and as many have already says, he comes across as a throughly nice, humble, modest chap. And that post on his website, praising Chelsea and their fans, very classy.
3. The beard

4. De Gea

What a guy. Very touching scenes with that hug, and the texting! Genius Dave. We should now be looking to create our own Spanish Armada, use these guys to recruit the likes of Koke, Saul Niguez and Oliver Torres.
5. The final, and most important point - Juan Mata is a Manchester United player. As in, he plays for us now. He's a top-class player, who used to play for Chelsea, where I assumed he would be for a long time. Maybe move to Madrid, Barca, PSG for big money. But no, now he plays for us. It's going to take a few days for that to sink in fully (like it did with RVP). What a lift this is going to be for everyone associated with Manchester United
