PERHAPS it was the Red Arrows trailing red, white and blue smoke over Glasgow.
Perhaps it was the rendering of the national anthem without the verse I so enjoy. Perhaps it was the old lady in the Rolls-Royce. But there was definitely a moment when I almost thought: "What a pity that I only get to vote Yes once."
This was before my heart swelled with manly pride at the very sight of a Saltire and the sound of a few tunes, of course. Just the vision of a Scotland team in matching leisurewear was enough to make me think ill of all things British and ready myself for freedom's hour.
Back in mundane Wednesday night reality, I of course thought no such thing. They have to be kidding, surely? Is it seriously suggested that our opinions can be swayed, one way or another, by sport and its rituals?
Yes, it is. The claim would be comical were it not so revealing. Politicians and their camp followers truly believe the rest of us are so thick we can have our beliefs bent by a sporting event or a celebrity. The months and years Scots have spent arguing through the complexities of self-determination or the appeal of Union count for nothing, apparently, if they are handed a wee flag to wave at the right moment.
Sport is potent, I make no bones about that. Sport arouses deep emotions and lasting loyalties. A great many feelings to do with life and living can be compressed into a vicarious involvement in some contest or other. But the idea that sport can tip the balance in a vote on the future of a nation is straight out of the bread-and-circuses handbook.
Even the allegedly subtle version of the argument bears very little scrutiny. The notion that an entire country can be persuaded to feel differently about itself because the golf went well, or because the 700th anniversary of a battle has come around, is like a weird parody of psychological conditioning theory.
For one thing, it excludes the possibility that grown-ups might just be slightly more concerned with the quality of their democracy, the survival of their health service, or what the future could hold for their children and grandchildren, than with a medals table. It also forgets that people actually do know the difference between the patriotism of the playing fields and loyalties that truly matter.
I blame Alex Salmond. If he hadn't let slip that he was obeying a "self-denying ordinance" to avoid talking about the referendum in the vicinity of the Commonwealth Games, Britain's buffer tendency would never have had their opening. Now he only has to describe Glasgow as "freedom city" in the making, and they apply for a gagging order.
The faux indignation is transparent, of course. What is really going on is a bid to shut off the national conversation for a couple of weeks while the referendum clock runs down. The idea that the rest of us should accept a political hiatus until the triathlon results are in or the lawn bowls contests are finished is typically outrageous. The assault on Salmond is, meanwhile, par - as they say in his favourite recreation - for the course.
You have to picture the scene, however, if the Team GB of politics got their way. Dignitaries from 70 countries and territories turn up in Glasgow. Dozens of those countries have achieved their independence from Britain. All of those countries are interested in the first event of international significance to have taken place in Scotland in a very long time. And Salmond says he cannot comment, for he must on no account "exploit" the Games?
But he's a cunning one, they' ll tell you. By his usual nefarious means he has somehow arranged an entire programme of 2014 events, from Homecoming to the Bannockburn anniversary, the Games to the Ryder Cup (which takes place after the referendum), just to bewitch us. He probably has a certified Yes-supporting border collie ready for the World Sheepdog Trials at Tain, a mere fortnight before we vote. If Scotland loses that one, only the sheep will have triumphed.
Politics, a sport in its own right, is a funny old game. Some people don't play by the rules. Those who have demanded there be not a peep out of Salmond on the referendum wouldn't call singing the national anthem political. They would see no politics in the gathering of the Queen's Commonwealth.
They wouldn't even notice that David Cameron and George Osborne came to Glasgow to make pitches for the Union just a few days ago.
In these arguments, only one sort of nationalism is noticed, even while numbers of Yes voters insist that they are not nationalists of any description. The British variety of nationalism is exempted from consideration, despite the Union flags and the Team GB rhetoric.
So the Games are passed as acceptable if they seem to demonstrate Britain's possessions past and present are better together. Anything else is damned as "politicisation".
In Salmond's case, the hoary old nonsense about keeping politics out of sport has now become a demand that he cease campaigning entirely while the Games are on. That sounds to me like a straightforward attempt to interfere in the referendum process - or, if you prefer, to nobble the opposition. The voters who couldn't care less about sport, never mind the rest of us, are entitled to feel aggrieved.
On the bright side, the fear that a few Saltires at the trackside could unleash a nationalist fervour at least has the merit of being droll. It demonstrates that few on the No side actually understand what they are up against. They persist in believing that an inclination to vote Yes is an atavistic impulse of the mob. One minute the lieges are getting rowdy over the badminton; the next they're storming polling stations.
How many votes will be won (or lost, according to preference), if Scotland does well at these Games? Very few, I'd say. Even if Salmond set aside that "ordinance", how much luck would he have in persuading Glasgow crowds to see the referendum as sport by other means? Judging by the cheers when the England team paraded around Celtic Park, Scotland fans are more mature than paranoid Unionists realise.
You can't keep politics out of sport, nor should you try. If nothing else, to try is profoundly patronising. The idea that a bit of pride over, say, Scottish swimmers could decide a referendum is fatuous and demeaning. It treats voters as fools. But that might explain the nature of so much of Better Together's campaigning.
If political choices hung on sport, the performances of the Scotland football team in recent decades would have killed off nationalism long ago. Instead, the No side alone has been demanding a halt to campaigning. These, too, are the games people play. There are no medals for guessing the reasons.