Peter Pan: I remember you being a lot bigger.
Captain Hook: To a ten year-old I'm huge.
Shoe-Stealing Pirate: I fancy them shiny shoes for my booty!
Peter: Well, I think you can get them at Armani.
Rufio: Looky, looky, I got Hooky.
Wendy: Boy, why are you crying?
Peter: I don't know. A tear for every happy thought.
Hook: [On Peter regaining his abilities.] I like, I like it, I like it! Oh, Smee, what a superb idea I've just had! Tomorrow, I'll make Pan's brats love me! Oh, Peter Pan will fly again, he'll remember how! If he doesn't, those dirty Lost Boys will jog his memory! Oh, yes, you'll see! He'll crow, he'll fight, he'll fly, and then... He'll die!
Answer: Neverland very much runs on "If you believe, it will happen" which is what Tink means during the meal when she says "If you don't imagine yourself as Peter Pan you won't be Peter Pan." So by the rules of Neverland, as soon as Peter believed it was real it was then real. The dinner was trying to teach him to believe as, in Neverland, if you don't believe it then it won't happen.