Because Mom and Hook went back in time using a portal. [Henry answers as if it's the most normal thing in the world, then takes another drink of cocoa. He finds it interesting that going back in time using a portal, not to mention a guy called Hook, are all rather boring and normal things for him to say. But such was his life as the kid with the heart of the truest believer and the family that he had.]

So what you're saying is; everyone here is basically cursed. No death. Time frozen. At least the cocoa is good though I suspect magic was involved in the making of it.