I don't know if he's the best teenager ever, but I'm not sure how many 16-year-olds have won a EC as a key player, and then at 17 delivered an incredible season finishing 2nd in the Ballon d'Or with a Barcelona side that certainly didn't have players like Ronaldinho, Iniesta, Xavi, Eto'o,….
He wasn't at his usual level yesterday (the team even less so), but still not bad (especially considering he had just returned from injury), in any case, every time he gets the ball, it's danger for the opponents.
Personally, I am absolutely delighted with his performances so far. He's only 18, and we'll see what the future holds.