It’s the memes wot won it. This shorthand definition of an image, video or cartoon — usually humorous and shared rapidly by internet users — is one of many explanations for the extraordinary results posted in Thursday’s British general election. Bundled off the campaign just three days before the poll because of a series of car crash interviews, the Labour Party’s Dianne Abbott coined the best and, as events would prove, the most accurate of them when the snap election was called seven weeks ago by Prime Minister Theresa May.

Her comment back then — “June means the end of May” — quickly went viral. When the final result was announced on Friday, Britain was still being led, barely, by May, who called the election to cement her authority and increase her majority. She landed up with neither. Having warned on the eve of poll that a loss of “just six seats” would mean a defeat, she lost a dozen MPs and was pilloried in her once adoring press as a broken-backed, caretaker leader whose demand for a personal mandate on a Brexit deal had been rebuffed by voters.

The extent of the Tory reversal, and the unanticipated Labour surge, was perfectly captured in the final constituency result, in Kensington in West London. There, homes change hands for £35m and residents include the Duke and Duchess of Cambridge and the Beckham family. But after three recounts, it went to Labour for the first time since it was created in 1974. Doubtless not all the super-rich endorsed the Labour manifesto promise of value-added tax on private school fees and a garden tax on the abundant 370m² homes there, but very possibly many of their children did. In the days preceding the poll, the Tory press presented Labour leader Jeremy Corbyn as a terrorist-hugging, Venezuela-loving extremist who, in the wake of the horrific terror attack on London Bridge, would leave Britain defenceless, bankrupt and blighted.

In 1992, when John Major, the Conservative prime minister, won a surprising election victory, a combination of newspapers and television accounted for a virtual duopoly of disseminating information. Now the most widely read newspaper in Britain, The Daily Mail, reaches only 3% of the adult population. But 12.7-million people — a quarter of all UK Facebook users — viewed videos posted by the hard-left, Corbyn-supporting Momentum network. Labour, outspent 10-1 by the deep pockets of Tory cash, knew how to reach and target its audience.

One of its key targets was the youth vote, normally apathetic but switched on by the authenticity of Corbyn and his anti-austerity, positive messaging. It was almost a replica of the hugely successful campaign of another white-haired socialist across the waters, Bernie Sanders, in the 2016 US Democratic Party primaries. In the US primaries and the British elections, young millennials registered and voted in record numbers.

Some perspective is required. Famously, Sanders surged in the polls but ultimately lost the party primaries to Hillary Clinton. Corbyn defied the doomsday scenarios written in advance for him that confidently predicted his leftist manifesto and leadership deficit would result in his party losing perhaps 100 seats instead of the 36 it gained and shedding, not increasing, its vote 10%. But Corbyn’s party still fell 50 seats short of the finish line to Number 10 Downing Street.

However, if ever two female candidates mimicked each other closely, it would be hard to find a more unfortunate duo than Clinton and May. Both were assumed to be certain winners and, in different senses but perhaps for the same essential reasons, both lost.

May’s now thoroughly discredited advisers built the campaign around the cult of her personality, stressing the leader and not the party. “Strong and Steady” was her mantra but, on closer inspection and after disastrous policy reversals in the middle of the campaign, voters decided “weak and wobbly” was a better fit.

In 2016, soon after David Cameron’s Brexit misfire thrust an unelected May into Number 10, a Guardian journalist coined the best moniker for her — “Maybot”, signalling her mechanistic, humourless and defensive personality. This was amply on display during the campaign when, having banged on about leadership, she refused to debate her opponents. Having demanded a strong hand for the Brexit negotiations she refused, beyond slogans, to reveal the colour of her cards.

Last Thursday night, I was at a dinner in London hosted by a Conservative parliamentarian friend. Fine wines and champagnes were served in a celebratory atmosphere as our host relayed that his party’s central office was calling a majority of 60 seats. When the exit polls at 10pm suggested, with accuracy, that it would be a hung parliament, our host’s face assumed a funereal look.

But he had intuited a deep dissatisfaction among voters. Young people left university saddled with debt and unable to buy a home, he said. And across the country, voters were “sick of austerity”.

He pointed out, again with accuracy, that the brightest hope for a Conservative future lay in Scotland, where an impressive lesbian kickboxer, Ruth Davidson, won many seats. The Scottish voters saved the day for the Tories and the huge reversal of the hitherto invincible Scottish National Party probably puts paid to dreams of independence.

May, still in office but bereft of much power, can now govern only with the assistance of hardline Ulster Unionists from Northern Ireland. If Davidson in Scotland represents the detoxification of the Tory brand, May’s new allies from Northern Ireland, anti-gay and pro-life, represent its opposite.

But these are matters of culture and style. Far more urgent are the Brexit negotiations with Brussels. This was where May’s enormous miscalculation of calling an election not only misfired but doubled down on the enormity of Cameron’s decision to call a referendum he believed he could not lose.

Now Brussels is united and Britain is divided on the very issue that will define the future of trade and the economy for generations. The negotiations start in a week, headed on the British side by a prime minister of little authority and less credibility.

Big events and rebellious voters — in the US, France and Britain — are confounding the pollsters and upsetting the complacent plans laid out by leaders. When will this political tidal wave wash over our southern shores?

• Featured in the Business Day