First, he hemmed me in, then he wound down his window to demand to know, with a face pinker than raw gammon, what I was doing driving the wrong way round a one-way car park.
I explained that I'd never been to that particular car park in Dublin before and, obviously, didn't know it was a one-way system, otherwise I wouldn't have been going round it in the wrong direction, would I?
As I was talking, he stared at me quizzically, eventually noting my Northern Irish accent and then, looking me straight in the eye, said: "We're civilised down here."
"Civilised," he added, triumphantly, just in case I hadn't got the point.
Anyone from Northern Ireland will be familiar with the smug air of superiority that comes over people south of the border when they're forced to acknowledge the existence of northerners.
Most of the time, they try to keep it under wraps, but at moments of annoyance it just bursts out.
It's a weird mix of condescension and contempt, all wrapped up in the absolute conviction that they're just more, well, civilised than you are and that you should be grateful they let you come to their precious capital city at all, rather than being sent back to the savage northern wilderness where you belong.
Whether he meant it that way or not - and he probably didn't, because he's a decent man - that was the attitude which came through from Fianna Fail leader Micheal Martin's latest remarks, explaining why he thinks Sinn Fein is not a suitable coalition partner for his party in the Dail, despite the fact they're a part of government in Northern Ireland as of automatic right.
The question has been given new urgency by the calling of a general election in the Republic for February 8.
It's unlikely either of the two main parties will win enough seats to take power alone, so the question of who to bring in as coalition partner has returned to haunt the contest.
Fine Gael has been playing footsie with republicans for the last few years, as Taoiseach Leo Varadkar sought to build an anti-Brexit alliance.
But getting into bed with Mary Lou McDonald would probably be a step too far for the party's respectable, middle-class supporters.
Micheal Martin, meanwhile, has steadfastly ruled it out, even though many of his colleagues think Sinn Fein, as long as they behave themselves, would make a natural fit. If Sinn Fein is so unfit for government, why do these people demand that it be done in Northern Ireland?
Micheal Martin acknowledged that there was a difference in his attitude to Sinn Fein's participation in government north and south, but struggled to justify it, despite referencing the fact that the security services have consistently flagged up the continued existence of the IRA army council and its influence over political representatives.
It's not just about government, either.
Mainstream political opinion in the Republic was equally hypocritical about the release of prisoners under the Belfast Agreement.
They insisted that it was right to let out those who had murdered RUC members, while being horrified at any suggestion that the men who shot dead Garda Jerry McCabe during a botched post office van raid in Co Limerick in 1996 should benefit from the same deal.
The implication appeared to be that it wasn't as bad for republicans to kill serving police officers in Northern Ireland.
This insufferable sanctimoniousness is echoed in attitudes towards social issues, such as same-sex marriage.
It's common to hear sniffy commentators in Dublin dismiss people in the north as backward for not, as they see it, embracing progressive change in the same way that the Republic has.
In fact, public opinion in Northern Ireland is no less liberal. A 2018 poll put support for same-sex marriage here at 76%, significantly higher than the 62% which voted for it in Ireland's 2015 referendum.
It just so happens that legislative change was hampered by local political difficulties, that had to be overcome by the intervention of Westminster.
It doesn't mean that people here are any less enlightened than self-congratulatory citizens a few miles down the road.
That's what made it so interesting to observe the recent row over the Irish government's plan to commemorate members of the Royal Irish Constabulary and Dublin Metropolitan Police, who served in uniform during the pre-independence period.
Ministers were forced to cancel the planned, one-off, small-scale commemoration, intended as part of an ongoing Decade of Centenaries, after an outburst of hysterical outrage from nationalists, who chose to portray it as a calculated insult to those killed in that era by pro-British forces.
Not unreasonably, unionists took a clear hint from this that, for all republicans' promises to cherish British identity in any future united Ireland, the reality is quite different.
The row demolished the Irish Republic's smug conviction that they're above the tribal excesses of Northern Ireland.
Throughout the Troubles, the tone of much southern commentary often went no deeper than asking why people 'up there' couldn't all just get along with one another, instead of coming to blows over matters of identity.
If only nordies were as reasonable as us, they tut-tutted, things would never have got out of hand.
The same, sneering attitude invariably seeps through when negotiations between parties here break down periodically.
It's as if we're savages who must be saved from our worst natures by the benevolent intervention of wise heads from Dublin and London.
Northerners must be forgiven our amusement to see how easily people who were once so sure that they were above all this ethnic conflict suddenly went full 'tiocfaidh ar la', like Martina Anderson at a hunger strikes rally, just because they were asked to remember fellow Irishmen who happened to be on the 'wrong' side of history in the run-up to partition.
Public opinion in the Republic - not just among Sinn Feiners, who fall into sectarian rhetoric like a drunk tumbling off the wagon, but from otherwise sensible people, too - couldn't even cope with being reminded that there were plenty of Irish men and women a hundred years ago who didn't want to leave the British Empire and that they shouldn't be airbrushed from memory.
The row ended with the Wolfe Tones' version of Come Out Ye Black and Tans at number one in the music charts.
It didn't take much, did it? One scratch on the surface and all the tribalism came oozing out.
Seems people in the Not So Beautiful South aren't so different from those of us in Northern Ireland on whom they've looked down their noses for years.
Call me petty, but I like to think that yer man in the car park was one of them.