[He bites back his initial reaction of You don't know me, partially in an effort to not be abrasive...and in part because that means he doesn't know her, either. He forgets, sometimes, that there are some people who just care. Reminding himself of that makes him rethink his response.]

I... [For as old as he is, there's a moment where he suddenly feels like he's ten again, being gently scolded by his grandmother. That moment doesn't last, but the feeling, the desire to prove himself worthy of the worry, does.]

I think we have to be. Whatever brought us here...we've gotta assume it's capable of anything. Which means not being impulsive. [... Which, if the slight reluctance in his tone is any indication, might be a little tough for him.]