I just baked cookies! Give me some constructive criticism on this introduction and I'll give you one :)?

Cliche from what I skimmed... it just sounds like a ton of other books that started in very similar ways. If I read that in a book on the library I would put it back after the "never, ever leave." because that makes it feel like one of those "You may not stop after you start reading this!"..."you will die if you don't repost!" messages that are all over other sites. Also, I think you repeat "You don't want to enter this world" in different ways a couple too many times. What I do like is the second and third paragraphs though :) The part in the fourth where you say "we'll talk about that" takes the reader completely out of the story. It's like a blue horse in the middle of a herd of zebras; it doesn't fit and it takes away from the rest of what's there. I would just not mention at all, that would make it much more child-friendly if that's your target audience. Also, how do we keep the population going without ? Just a thought ;)