"No, you're not," Jack contradicted softly. "Hell, if you were fine after everything that's happened this last week, you wouldn't be human."
And he might not have very clear memories of being 18 - or, for that matter, any memories of being 18 - but he was pretty sure he wouldn't have been able to deal with practical knowledge of the nature of time and causality at the same time as losing his virginity to his centuries older self.