I'll just immediately automatically, without even thinking, check my phone. And it feels like the same little bit of my brain is being - the synapses are lighting up when I do that.

It's a barrel of laughs, isn't it? It makes The Day After look like friggin'...insert name of cheerful thing here. It was one of the things that made me really worry about worst-case scenarios. There's something impish and probably somewhat therapeutic about thinking about those things.

That's not something that we've gone in thinking 'Right! How are we going to examine that now?' It's just when you take a step back you see that they're actually all sort of in that mode.

Technology is a global thing and wherever you go, people are prodding the same devices and worrying in the same way and have had their lives slightly altered in the same way.

[My parents when I was a kid] would go, "It's a nice hot day. Why are you inside watching the TV?" And you go, "Well, 'cause it's better?"

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"]."

In Britain people might know me more for my comedy writing background, things like that.