Just after the United Kingdom voted to leave the European Union last summer, a young man from Holywood, Co Down, pondered the future.
"If I'm Northern Irish, what's better?" he wondered. "To be part of the UK and not be in the EU? Or to be in a united Ireland and still belong to the EU? People are going to have to weigh that up."
The young man concerned was Rory McIlroy.
As a multimillionaire who plays golf with Donald Trump, McIlroy may not be the most renowned political commentator - and he is not your typical young Northerner. But Brexit has certainly made people think seriously about a united Ireland, both North and South of the Border.
And this has been underlined even more after the historic results of Northern Ireland Assembly elections, when the unionists lost their majority in a parliamentary assembly for the first time.
Back in the 1980s, the unionist citadel seemed impregnable, despite the violent mayhem that continued to be unleashed across the North. In assembly elections in 1982, the unionists had 51 out of the 78 seats.
Now they are down to just 40 out of 90 seats, and their support seems to be showing an inexorable decline.
In the North's main city there was talk this week of the "greening of Belfast", with unionists winning only six out of 20 seats. The Union flag no longer flies throughout the year on Belfast City Hall, and street signs in Irish are a common sight in many areas.
Until now, a united Ireland seemed like a pipe dream, a pious belief that was part of the Sinn Féin and Fianna Fáil creed. It seemed about as credible as stories of moving statues. The notion seemed so far-fetched that few felt the need to explore the practicalities.
But that view is changing. As Siobhan Fenton put in the London-based Independent this week: "Ireland now looks set to join the roster of political shocks and upsets we have seen rippling across the world. Here's a sentence I never thought I'd utter: for the first time in my lifetime, a united Ireland is now credible - and perhaps inevitable."
The Taoiseach Enda Kenny certainly has reunification on his mind. He recently told a private Fine Gael function that Britain's exit from the EU could result in an "uncomplicated route" to a united Ireland.
He also said recently that any Brexit deal should include language that should allow the North to return quickly to the EU in the event of reunification.
Kenny said the provisions that allowed East Germany to join West Germany and the EU "in a seamless fashion" after the fall of the Berlin Wall offered a precedent.
So is the notion of a unified country of 6.6 million people really credible, and what would the country look like? Would it be run from Leinster House, with the likes of Arlene Foster and Ian Paisley Junior commuting down to Dublin as members of a minority party in a 32-county assembly, and will they be popping over the street for pints in Buswells Hotel?
Would RTÉ have to ditch the Angelus bell before the Six-One News as it takes over BBC Northern Ireland, and would the Catholic Church give up control of schools in order to accommodate an enlarged Protestant minority. And could we bear the cost?
If nothing else, a united Ireland would give us a greater chance of winning the World Cup in football. As a result of Partition, we have lost out on such legendary names as George Best, Derek Dougan and Pat Jennings - and a united Ireland would surely increase our haul of Olympic medals.
Professor Kurt Hübner of the University of British Columbia is one of the few academics to have studied the effects of unification in Ireland. He is surprised there is little detailed examination of the shape of a united Ireland.
There is a common view that the Republic could not afford a united Ireland, but Prof Hübner believes the financial result would be overwhelmingly positive. Before the Brexit vote last year, he produced a study forecasting that the end of Partition would benefit the entire island by more than €35bn over eight years.
Prof Hübner says having two governments on a relatively small island creates enormous inefficiencies and trade would be improved by tax harmonisation and the removal of barriers.
"Now that Brexit is happening, from an economic point of view the case for unification is stronger than ever before," the academic tells Review.
Prof Hübner says getting rid of the Border would protect Ireland from a surge in costs caused by Brexit as a result of increased paperwork and possible tariffs on exports and imports across the border.
"I wouldn't say that Brexit will be a catastrophe for Ireland, but it will have huge costs."
The academic, who lived in Berlin through German reunification, says the country should be prepared for a united Ireland.
"I lived in Berlin in the 1980s when the wall was there, and people did not expect the unification of Germany, but things can change very quickly."
Tom Kelly, who chaired the campaign to stay in the EU in the North, believes a united Ireland is inevitable, but forecasts that it won't happen in the next decade.
"I would put a timescale on it of 20 to 25 years," says Kelly, a former vice chairman of the SDLP.
The major reason why a united Ireland is considered more likely now is the rapidly changing population in the North. Figures from the 1926 Census showed that two-thirds of the population was Protestant and one-third Catholic. Now the Protestant population has dropped to 48pc, while Catholics number 45pc.
The numbers adhering to neither of these groups is also growing. There is also increasing secularisation, as young Catholics and Protestants keep away from churches.
Kelly believes it would be wrong to translate the vote to Remain in the EU and recent surge in support for Sinn Féin into a vote for a united Ireland.
A considerable number of unionists voted to stay in the EU. Many Catholic voters and others who voted for non-unionist parties are not necessarily supporters of unification.
"Sinn Féin ran a clever campaign, and won support from people who wouldn't be part of their core vote. They campaigned on issues such as same-sex marriage and abortion rights, and won a lot of support from young people as a result," says Kelly.
He believes that if a united Ireland is to take place, nationalists will have to do more to convince unionists, rather than relying on a tribal headcount. "They have not really done enough to act as persuaders of the unionists that they can exert more influence in a united Ireland than as 3pc of the population of the UK."
Kelly says a lot of changes will have to take place in the North before the two parts of the island come together, particularly in areas such as education.
He says Protestants and Catholics still lead parallel lives, and can still go through school without encountering each other.
"I myself did not talk to a Protestant until I was 20.
"Integration has been very slow in education. Many parents say they want an integrated education for the children, but in practice their children are still educated in separate schools.
"Integration will be difficult in many areas, because those areas are either predominantly Catholic or Protestant. If you are in an area that is 90pc nationalist, how can you integrate?"
The two communities have clung to their faith-based schools, but in some areas a compromise is being reached so that Protestants and Catholics share certain facilities. In a disused army base in Omagh, a campus for six schools is being developed. There will still be Protestant and Catholic schools, but they will share sports pitches, gyms and arts amenities. As it casts flirtatious eyes towards the North, the Republic would have to improve its health service. The National Health Service (NHS) operating in the North may not be perfect, but citizens there would not give it up lightly, unless the HSE was given a thorough revamp. In the North, a much lower proportion of the population feel the need to resort to private healthcare, and GP services are free for everyone.
Kelly says there is already close co-operation in healtchcare services between North and South. Altnagelvin Hospital in Derry is the regional cancer centre for the North West, attracting patients from Donegal. Thousands of patients also cross the Border to avail of free GP treatment in the North, but the funding of these services is now in doubt as a result of Brexit.
In many areas of the North, residents have not waited until a united Ireland to assert their Irish identity. The Irish language movement is thriving, with mini-Gaeltachts popping up across the North.
"Gaelscoileanna are the heartbeat of the Irish-language movement. They are the fastest-growing schools in the education sector in the North," says Ciarán Mac Giolla Bhéin, advocacy manager of Conradh na Gaeilge in Belfast.
He himself was educated through Irish throughout his school years in Belfast. The residents of a growing number of streets in Belfast and elsewhere are voting to put up bilingual street signs, much to the annoyance of some unionists.
"In Newry, the signs telling people that they are entering the council's area are bilingual, and some of these signs have been targeted by vandals," says Mac Giolla Bhéin.
A united Ireland may be reappearing on the radar, but the plans for this eventuality by Fine Gael and Fianna Fáil are decidedly vague.
Fianna Fáil has long cherished the idea, but the topic does not feature prominently on its website.
Darragh O'Brien, Fianna Fáil's foreign affairs spokesman, says the party is currently drawing up a policy document on the issue.
"A united Ireland continues to be our goal but not in a simplistic tribal way.
"We would have to look at whether we have a federal Ireland, a Dublin Leinster House government, or whether we retain any element of Stormont."
In the early part of the Troubles, republicans recommended a federal structure with parliaments for each of the provinces, and a central parliament based in Athlone. However, the Éire Nua concept became unfashionable, particularly among Northern republicans, because it was felt that it could be used by Northern unionists to reinforce their dominance.
Tom Kelly says one option would be to have Ulster unionists strongly represented in a reformed Seanad.
Kevin Meagher, author of the book A United Ireland and a former advisor to Labour Northern Ireland Secretary Shaun Woodward, says the Irish Government should be preparing for an end to Partition. "Britain does not want Northern Ireland and nobody in Westminster cares about what goes on there so long as people are not shooting each other and bombs are not going off.
"People have to realise that there has been a gradual population shift that makes a united Ireland inevitable.
"The Assembly election has shown that we have reached a tipping point with the loss of the unionist majority and nothing will be the same again."
The idea of a "border poll" has frequently been mentioned in recent weeks.
The Good Friday Agreement says the Northern Ireland secretary can call a referendum on Irish unity, if it appears likely "that a majority of those voting would express a wish that Northern Ireland should cease to be part of the United Kingdom and form part of a united Ireland".
The idea has been floated more regularly recently as a result of the Brexit vote, and the loss in Assembly elections of a Unionist majority.
A majority of the North's population would have to vote to secede from the United Kingdom and join a united Ireland for Ireland to move towards unification.
Voters in the South would also have to vote in favour of unification, in a separate poll.
If both parts of island vote for unity, negotiations will begin between governments and the main parties over the formation of a 32-county state.
The current Northern Secretary, James Brokenshire, said last year after Britain's vote to leave the EU that he did not believe that the conditions required to call a border poll had been met. British government sources indicated this week that this view has not changed.