I'm guessing "he busted his ass for years, toiling in ECW at best, then finally got to wrestle, for a title, in WWE, at MSG, and fans were chanting his name". Shit, how would you feel if you got to wrestle in your hometown (or at least somewhere close enough) after so long?
He just seems so natural. That's what I love about him. Anytime RVD has to do anything but jump around for no apparent reason, it seems forced. Selling, acting with his facials and et cetera. Book just does everything so naturally.