It was 4 a.m, on June 24, 2016 and the midsummer sun was just beginning to light up the London sky. Nigel Farage, then-leader of the UK Independence Party and a decadeslong "Leave" evangelist, emerged to enrapture his supporters with the words: "Dare to dream that the dawn is breaking on an independent United Kingdom!"

The referendum results, pouring in from across the country, were beginning to show an undeniable trend: After 43 years, Britain had decided to leave the European Union.

"We have fought against the multinationals, we have fought against the big merchant banks, we have fought against big politics, we have fought against lies, corruption and deceit," said Farage.

He chose to cast the moment of triumph in terms of the little guy taking on the world of high finance, and winning. Some thought this was a curious way to frame a vote on EU membership, but it was a telling insight into the terms upon which his side had conducted the campaign.

The economy, stupid? Not really

The referendum had been remarkable for how dramatically different the Leave and Remain camps had approached the campaign. 

The Remain side had been almost entirely focused on warning about the economic damage of Brexit, often drawing on the work of international bodies such as the International Monetary Fund to make its point.

Even US President Barack Obama visited London two months before the vote to issue some dire warnings. "The UK is going to be in the back of the queue," the former president warned about Britain's post-Brexit prospects of striking a trade deal with the US.

The tide of expertise about the economy was having the opposite effect to the one intended by the Remain side. Indeed, one of the most famous and prescient quotes of the entire campaign came when the conservative politician and Leave advocate Michael Gove said: "I think the people of this country have had enough of experts."

In fact, the Leave side, barely mentioned the economy in its official messaging. Its campaign, led by political strategist Dominic Cummings, was based around one central slogan: "Take Back Control." It was a simple but seductive message that could be applied to anything.

While leading Remain voices warned about the trading complexities and consequences of leaving the EU's single market or customs union, Leavers were talking about border control.

The Vote Leave website, still online and enshrined as a digital monument to the campaign's triumph, is a stark reminder of the selling points which appealed to the 17,410,742 people who voted to leave the EU.

"What would happen...if we vote to leave the EU," it invited the user to find out. "We will be able to save £350 million [€410 million/$488] per week," it went on, in a spectacular untruth regarding the cost of the UK's membership in the EU. That number became iconic during the campaign, with Leave saying this imaginary sum could be used to fund the country's widely beloved National Health Service. Despite having no basis in fact, it resonated with voters.

The phrases "We'll be in charge of our own borders" and "We can control immigration" also featured prominently, and warnings about Turkey joining the EU were touted. Since the referendum, various studies have established a strong connection between those who voted Leave and anti-immigration sentiment.

The only real economic benefit noted by Vote Leave was:"We'll be free to trade with the whole world." The campaign argued that the EU was preventing the UK from signing trade deals with "key allies like Australia or New Zealand, and growing economies like India, China or Brazil." Should the UK break up with the bloc, Vote Leave said Britain would be "free to seize new opportunities which means more jobs."

Post-Brexit trade with the EU was barely mentioned by Vote Leave, but when it came up in debates it was almost exclusively sold as a given that the UK would continue to trade on the same terms with the rest of the EU after it left the bloc. A "no-deal" scenario, which came close to reality several times, was not even a discussion point.

Reality hasn't quite intruded yet

The 4 1/2 years which passed between the vote and the UK's full exit from both the EU and the post-Brexit transition period on December 31, 2020 were filled with endless twists, turns and political intrigue.

Much of it was taken up with debates over competing visions of Brexit, particularly around membership of the single market and customs union. Theresa May, prime minister from July 2016 to July 2019, tried several times to secure a Brexit which would have kept the UK in the customs union, but she never garnered enough support.

The EU and UK's Brexit deal, officially called the EU–UK Trade and Cooperation Agreement, came into force in January 2021. The pandemic has greatly complicated meaningful economic analysis for the period since, but there is already evidence that Brexit has fundamentally changed the UK's economic relationship with the EU.

Recent UK government figures showed that trade with the EU has fallen by 23% since January, while a study released in May by experts at Birmingham's Aston University found that Brexit had reduced UK services exports by around €128 billion over a four-year period.

In terms of trade deals, the UK has so far struck just one that it did not already have as an EU member, that being the agreement it recently reached with Australia.

Any potential benefits from that or other future deals are clouded by the continuing uncertainty over how the UK's trade relations with the EU, still its biggest trading partner, will evolve. The Northern Ireland Protocol, which concerns customs checks between Northern Ireland and the rest of the UK, remains a source of serious dispute.

A state of mind, not a state of trade

But, five years later, there is a sense of irrelevance to the economic arguments around Brexit. That's because they don't go to the heart of why so many voted to leave.

Remain arguments about the economic consequences did not stick in the many regions of the UK where unemployment, deprivation and poverty were already high. The vagaries of customs unions or single market membership were not seriously considered by a majority of voters.

As the years go on, it will become easier for economists to analyze just how positive or negative Brexit has been for the UK economy. Yet regardless of what that future data shows, it may not make much difference to those who voted Leave.

Opinion polling shows that another referendum on EU membership would still be tight. A YouGov poll in May 2021 found that 45% felt the UK was right to leave, versus 44% who felt it wrong. The ruling Conservative Party, stacked with Leave voices in Cabinet, remains popular with voters.

Most crucially, it is words like sovereignty and control that still appear to stir the passions of voters, not the lexicon of EU exports and imports. Clearly, for many millions, Brexit is a state of mind rather than a state of trade.