"Not being twenty-three." He explains, and while it's a bit flippant, how do you explain to someone that you've lived for nearly twenty years in the most dangerous job in London, and you've not died yet? There's no set of guidance he can explain to her, not quickly and easily anyway. He can go through the spiel he does for trainees, but he can't actually do that either, because she's not from a world where it will make sense.

"I do. And you'll just have to not trust me on that."