Overall, looking at the stories [Black Mirror], almost every story we've ever done is concerned with authenticity or reality in some way.

Am I living in a simulation?

We take things that would have struck us as miraculous five years ago for granted. Like Pokémon Go would have been insane, and now it's just like, "Oh, okay."

My wife made me watch this documentary about the Iraq War, and there was a really powerful moment where they followed some civilian whose family had been killed. This was 5 or 10 minutes of this woman talking, and it was extremely arresting. You realize how you never hear from the person on the receiving end of a war without a reporter stepping in to compartmentalize the story. Usually they're just a few shots at the end of a news report, wailing and screaming at a funeral.

My theory is that we used to have several personalities, and now we're encouraged to have one online.

"National Anthem" was just a funny idea I'd been knocking about. I initially thought about a beloved celebrity having to do that - and then I watched an episode of 24. In my head, I was writing almost a parody of a 24-style president woken in the middle of the night with a crisis. It seemed more interesting to play it ultrastraight and to have the viewer's initial reaction be one of laughter and disbelief - and just have the whole thing become progressively more uncomfortable.

I actually had that conversation with [Channel 4 Chief Creative Officer] Jay Hunt. We were at a bit of a crisis point. I'd written a totally different script - about war, basically - that got rejected at the last minute for various reasons. The whole of the series was in doubt. I said, "Well, there is one other idea ["National Anthem"]."