You shouldn’t be able to do any of this. You shouldn’t be so… so rational. You shouldn’t be able to stand here discussing this with me calmly and coolly. And, much more than any of that, you should not have been able to break off mid-hunt with the scent of human blood in the air. Even mature vampires have difficulty with that – we’re always careful of where we hunt so as not to put ourselves in the path of temptation. Bella, you’re behaving like you’re decades rather than days old.
Edward Cullen, Breaking Dawn, Chapter 21, p.420