I don't know why anyone bothers adding captions like "That's the truth" when talking about future events. I can only presume you want not to be taken seriously.
As for Nadal and grass, he lost to Müller and Rosol in R2, he would have lost to Youzhny in R4 2007 but for the Russian injuring himself halfway through, he was in severe difficulties against Kendrick in R2 2006, Haase R2 and Petszchner R3 in 2010. Sure, Federer has also had troubles against Falla and Benneteau, but those are the only two five-setters before the QF for him since he beat Sampras in 2001. So it's obvious which of the two is best week one. In week two, the difference becomes much smaller.
And that really is the truth.