Dominic Cummings is brash, contrary and unpredictable. In a rare interview for a book I co-authored with Paul Goldsmith called How To Lose A Referendum, the former campaign director of Vote Leave told me about his life, his campaign techniques and his strange relationship with politics.
Speaking earlier this year at his home in London I found there was something both refreshing and unsettling about his lack of caution in the language he used to describe people and events.
When talking about his determination to win the campaign at all costs he observed that people didn't realise he would "happily chop David Cameron's head off, every day, in order to win."
At one point he referred to the migrant crisis in Europe as "worth millions in advertising" as we discussed the impact of this event on the referendum campaign.
The eurosceptic strategist also had no qualms confessing that he thought Eurosceptics were "particularly unbalanced." And in his view some of the MPs he worked with during the campaign were "completely deranged."
Indeed the man who chose politics as a profession seems to dislike politicians in general. He says Parliament consists of people who "to a large extent are not particularly bright, are egomaniacs and they want to be on TV." He believes the selection processes for MPs and the incentive structures within parties mean that the wrong candidates are attracted to the job.
Certainly it came as no surprise to me that Cummings now says that the UK's decision to leave the EU may turn out to be "an error." Let's be clear, he also thinks it may still be a success, but he has never been a purist, evangelical member of the eurosceptic church.
After months of silence about Brexit he has also jumped furiously to the defence of the UK's membership of Euratom (the EU's nuclear power regulator) and warned that Theresa May's Brexit plan is "unacceptable bullshit."
David Cameron once described Cummings as a "career psychopath" but here is another contradiction - because while he has cultivated a reputation as mad, bad and aloof what I've learned is that he has a real talent for listening to people. That's what helped him develop the slogans that persuaded the UK to tick the box marked "Leave" in the EU referendum.
He was born in Durham and his father was a project manager for the construction of oil rigs and other large structures. Cummings stayed out of politics while studying at Exeter College, Oxford, where he earned a first in ancient and modern history. Then, after a period in Russia, he joined Business for Sterling in 1999, the campaign to stay out of the Euro.
Here he became an expert in running focus groups - listening to public concerns about the currency and working out what messages they were most receptive to. During this time he also started to lose respect for politicians. He told me that very soon he decided that "99% of MPs are dreadful characters and if you want anything professionally organised you've got to exclude them, which causes a lot of trouble."
Excluding certain politicians from his operation nearly got him ousted from Vote Leave in February 2016, but at this stage he'd created a loyal team around him and these crucial staff members threatened to stand down on mass if the MPs and donors sacked Cummings from the campaign. This was shortly before his good friend Michael Gove and Boris Johnson joined Vote Leave.
He believes that part of the motivation for the attempted coup was because certain MPs didn't want Johnson or Gove running the campaign, as it would deflect the limelight from them.
Cummings describes the Eurosceptic world as "populated by very odd people. Generally, not always but generally, the longer they have been involved in it, the higher the probability that they will be odd."
He adds: "the cumulative effect psychologically of being called 'nutters' and excluded from things means they become more eccentric over time."
He could perhaps apply this science to his own personality. Opposition to the EU infused his psyche over the years. After working for Business for Sterling he had tried and failed to set up a group called New Frontier "to figure out the whole roadmap of getting out of the EU." But, he says, everyone fell out with each other "in classic eurosceptic fashion."
In 2004 he campaigned in the North East against John Prescott's plans to create a regional assembly which he says was "a kind of training exercise" to learn how the referendum process worked. His campaign depicted the assembly as an expensive talking shop without any real powers and they won with 78% of the vote, beating the better resourced establishment campaign. It was the first time that Cummings sensed the growing void between the northern heartlands and Westminster. He says: "We exploited this feeling. 'Politicians talk, we pay' was our slogan." He would exploit the feeling again during the 2016 referendum campaign.
From 2011 to 2014 he worked for Michael Gove at the Department of Education and was considered to be the brains behind Gove's schools reform programme, but even during this time he would often bring up random questions in his education focus groups to test the public mood towards the EU.
After leaving the department in early 2014 he was commissioned to conduct public attitude research on the European Union for a new group set up by Matthew Elliott called Business for Britain (BfB) It would become Vote Leave. As a result of this research Cummings produced a document which has never been published but is probably one of the most significant factors of the campaign. It formed the blueprint for Vote Leave's strategy.
The 19-page report (which we obtained for our book) contained the word "control" 37 times - mostly used by members of the public with reference to numerous issues where they felt control had been lost to the EU, commonly in relation to immigration. "We've lost control - because of the EU," says a man in Thurrock.
In his report Cummings concluded that in a referendum, "it would be important for the OUT campaign to avoid taking specific positions on many issues as this would only split the campaign. Instead, the OUT campaign should simply say 'whether you think X or Y about Z, the most important thing is we take back control of Z'".
He also discovered from his focus groups that, apart from immigration, "the strongest argument for leaving is 'we will save a fortune and we can spend that on the NHS'". Sound familiar?
Simply by listening to the concerns of members of the public Cummings and Elliott developed their two most powerful slogans: "Take Back Control" and the controversial "350 Million to the NHS."
These were not the works genius advertising gurus, they came from the mouths of ordinary people, which made them all the more potent. "I just listened," says Cummings.
Vote Leave's precursor Business for Britain was essentially set up by Matthew Elliott to
ensure that Nigel Farage was not the front-man of the Leave campaign, amid concerns that his messages on immigration were off-putting to the core swing voters needed to win.
Elliott decided to create a business-led Conservative campaign to attract the likes of Michael Gove and Boris Johnson into a mainstream Leave camp - with its core argument focused on global free trade and the erosion of UK sovereignty by the EU.
And yet the Cummings report for BfB in 2014 established that immigration and the ability to implement Ukip's policy for an "Australian-style points system" was the most powerful argument for leaving the EU.
Cummings found that if during his renegotiation David Cameron was to "fail to take back control of immigration policy from the EU... voters will regard the renegotiation as a big failure."
He went on that "the public already rejects the combined view about immigration of the three main parties" and therefore "it is unlikely that the pro-EU forces could change people's minds about immigration even if they spent tens of millions on brilliant adverts."
In his view this meant that, actually, the Leave campaign didn't need to focus on immigration until the later stages of the campaign because most people had already made up their minds about it. He told me: "From that report we decided immigration was such a big deal we don't have to make a big deal of it."
With the migration crisis as the backdrop leading into the campaign he would later tell his team. "There's nothing we can do that has remotely the force of what people can see on the TV of these guys getting on their boats and sinking."
When I asked him about the TV footage of the migration crisis on the news he said: "I don't know what kind of value you put on that in advertising terms, but if you talk about millions, tens of millions of pounds worth of essentially advertising of people on the news, and people watching that and thinking 'the world is changing fast and in a dangerous way, the EU is contributing to the problem and the guys in charge in London haven't got the faintest clue what to do about it.'"
According to the International Organisation for Migration 3,770 migrants were reported to have died crossing the Mediterranean in 2015. Yet here was Cummings brashly referring to its value in advertising.
In crude terms, he is right that the migration crisis probably did impact on people's views about the EU as did the Eurozone crisis and probably too the rise of terrorism in mainland Europe. You tend to think of Farage exploiting this misery with his 'Breaking Point' poster, but there's little doubt that Vote Leave's strategists were happy to let him do the dirty work.
The Cummings report from 2014 also identified the public mistrust of experts and authority. "They all lie, they don't care about us" is a quote he attributes to people he spoke to not just in one or two focus groups but "everyone, everywhere."
He observed: "A significant change in how people regard the economic arguments since the euro battle" as a result of the euro and financial crisis he added that: "The motives of big business are very suspect... given the extremely low opinions of the City and bankers, it is far from obvious that having Goldman Sachs on the side of IN is an advantage."
What is striking about the report is it could have almost been written in retrospect looking back at the campaign.
But it was produced a year before the 2015 general election, before the referendum was certain and 18 months before the Remain campaign was even getting mobilised.
When it comes to preparation Vote Leave was light-years ahead of their competition. Their secret weapon was Cummings - and his secret was a good ear for the public mood and a blunt application for turning it into winning messages.
Jason Farrell is a Senior Political Correspondent at Sky News and co-author of How To Lose A Referendum