In his new epic series, Curtis pulls together such disparate threads as Chairman Mao’s wife, Jiang Qing, the stoner duo who created the Illuminati conspiracy theory, Tupac Shakur, and Dominic Cummings. Through these personal histories – and many, many, more – the six-part film picks apart the rise of individualism, the fall of democracy, failed revolutions and corrupt systems of power, the addictive nature of social media and the combined psychological impact all of that has had on us.

If that particular synopsis makes it sound like the whole world is burning, while we sit helplessly and watch, Curtis wants you to know that is not his intention at all. While there are several points in the documentary that have quite nihilistic undertones, he directs me to the opening quote in the first film, by anthropologist David Graeber: “The ultimate hidden truth of the world is that it is just something we make, and could just as easily make something different.”

Ed Gein was the famous “Psycho” killer, arrested in Plainfield, Wisconsin, in 1957. A kind of American fable, if you like, and I really, really wanted to meet Ed Gein. I remember lying to people about how I had met him, when I hadn’t. And then I thought to myself, why lie about meeting him when you can actually meet Ed Gein?

I got in to see Ed, finally, because I had these letters of introduction from various forensic psychiatrists at Berkeley School of Criminology. The head of the hospital, Dr. Schubert, was probably as nuts as Ed Gein. I ask him if there’s any truth to the claims that Ed was a cannibal. He seems insulted, he says absolutely not. I asked Ed about this very issue, and he told me that, although he had tasted human flesh many times, that he didn’t like it.

See, I live for this kind of thing. It confirms some kind of satisfying idea about the world that the world is really fucked. It’s really insane. Our heads are such foreign countries. Such strange, uncharted territories. And it’s fun. It’s fun for me to talk to geniuses, it’s fun for me to talk to monsters.

“In its essence, Wormwood is a story about a very, very smart young boy, now a man in his 70s, who has been involved in an epistemological journey into the nature of his father’s death. And I like to think that the movie, in its attempt to examine these questions, matches his own sophistication about these questions. How do we know what we know? How do we know that my father was murdered? What does that murder mean? He asks this question again and again and again, particularly near the end of the film. It’s one of my favorite sections of Wormwood, when he asks, ‘What does it mean?’

“It’s the same question that I’m always asking: What does it mean? And this irony, which I learned from Eric, is not something I imposed on the material-the irony of, How much are we willing to sacrifice in order to know something? Knowledge comes with a cost. And to what extent is knowing something worth the price that we have to pay to know it? The other option is to live in a fantasy, but if you ask me if there’s anything that makes us great, it’s the pursuit of truth. It’s the fact that we attempt to reach outside of ourselves and to know something about the world around us, and ourselves.

Rather than deal with something complicated, Western powers found that Gadaffi who had until then been isolated and ignored by the Arab world, fitted the bill of a cartoon villain.

“Gadaffi illustrates, like a flash of lightening on a dark night, just how corrupt, how hypocritical, and how empty of values our middles class elites have become,” Curtis told us. “It was quite shocking to me. It’s just rubbish that he had WMDs. There were no biological weapons and he’d got a a centrifuge but none of his people knew how to put it together – it was in boxes.”

But after being demonised in the 1980s and 1990s, Gadaffi finds himself rehabilitated.

“After the Gulf War all these people go out and make him into a modern thinker: David Frost, Anthony Giddens, even Lionel Ritchie went out there, and said Gadaffi was good. Then, after they Arabs Spring he was a villain again, so they just dropped him.”

“I was thinking of making a sort of comedy…

After the broadcast of Curtis’s 2007 film The Trap, which traced the influence of game theory – the idea that humans behaved as self-interested individuals – on contemporary economic thought, Prospect magazine’s Max Steuer argued that the series “greatly exaggerates the power of ideas, and at the same time almost wilfully misrepresents them”. Others made similar criticisms of All Watched over by Machines of Loving Grace, which linked the anti-state philosophy of Ayn Rand with the “techno-utopians” who developed modern computing. At the very least, don’t his films encourage precisely that gloomy feeling – a sense that power is in the hands of an unaccountable elite – that so exercises him?

“Well, I am a creature of my time,” he concedes. We’ve found our way to a café in the shopping centre near Thamesmead, where we can chat at greater length. “What I’ve been trying to do is analyse why progressive ideas failed.

“Secondly, I’m interested in telling stories, because I like telling stories and I think ideas are important. I take particular influences of particular groups of people as a way of showing how that idea spread out. I never say this is where it all came from, this shadowy group of people. I’m telling you a story, like a novelist would, but as a factual story to try and bring it to life to you.”

The most distinctive thing about Rumsfeld is his use of language. Is it Orwellian? In 1984, language is used as a means of control-but it is conscious control. With Rumsfeld, I felt I was witnessing something more complex: a man using language to obscure the world from himself as well as from others. In his Pentagon press conferences he would frequently quibble over the meaning of words: “pre-emption,” “insurgency,” “quagmire.” It was almost a way of keeping a safe distance from reality.

Most people remember that Rumsfeld’s famous comment about “known knowns,” “known unknowns,” and “unknown unknowns” happened at a press conference, but few remember that it was in response to a question about what evidence we had that Saddam Hussein was linked to terrorist organizations-which was the justification for the war in the first place. The more I studied this performance, the more I realized that what Rumsfeld said wasn’t really an answer. It was an attempt to change the subject, to turn reporters’ questions about intelligence into a lofty question about the nature of knowledge: “Sometimes we have evidence for things and sometimes we don’t; sometimes we know what we’re looking for and sometimes we don’t.”

“Good Lord, it’s my past,” Morris says as he leafs through a box filled with folders labeled “Manson Girls” and “Lobotomy.” Many of the boxes are cardboard coffins for movies he pursued for years but couldn’t fund.

The central idea [of All Watched Over By Machines Of Loving Grace] leads Curtis on a journey, taking in the chilling über-individualist novelist Ayn Rand, former chairman of the Federal Reserve Alan Greenspan, the “new economy”, hippy communes, Silicon Valley, ecology, Richard Dawkins, the wars in Congo, the lonely suicide in a London squat of the mathematical genius who invented the selfish gene theory, and the computer model of the eating habits of the pronghorn antelope.

You can see why Zoe Williams once wrote that, while watching one of Curtis’s programmes, “I kept thinking the dog was sitting on the remote.”

TV industry! Here’s a little bombshell for you. From now on, all of Curtis’s work will be produced first and foremost for the internet. It will be hosted at bbc.co.uk/adamcurtis (coming soon). Go there to find a trailer for It Felt Like A Kiss. An hour-long cut of the whole thing will be placed on the site on the last day of the Manchester International Festival (MIF). It will also host his next two projects: “A long thing about our complicated relationship to the Congo over the last 100 years and how our idea of nature as a sacred yet terrifying realm has risen up during that same time.” That will be followed by a piece about “the political and cultural ideas that underlie the internet – and the idea that we are all linked in an interconnected web – out of which can come a new form of democracy.”