For those who haven't had the privilege, here's what being tear-gassed is like. The first thing you feel is a dry ache at the back of the throat, similar to the nocturnal sore throat that prefaces a chest cold. Next, a sharper pain erupts in the sinuses, spreading outwards. Only then do the eyes start to run, though not very much in my case.
But then, we were only collateral damage on this occasion, caught on the fringes rather than at the centre of the mayhem. We were not rioting nor even protesting, merely shopping, and while this activity has its dangers in my wife's company, these are generally financial rather than political in nature and of little interest to even the most baton-happy of the French riot police.
We first realised that the weekly rally of gilets jaunes protestors had adopted a new strategy when we were browsing the window display of an accessory shop in one of the twisting pedestrian streets of the Montpellier écusson (old town) for a plastic tiara to complete my granddaughter's princess dress party outfit.
A young assistant suddenly unlocked the door, which we hadn't realised was locked, ushered us in, then locked it behind us. Moments later, there was an eruption of whoops and whistles and a group of perhaps 20 masked youths in day-glo tabards charged downhill past the shop, watched with resignation by shoppers pressed back into doorways.
The assistant suggested that we and other customers might prefer to move to the back of the shop, since the protestors had a fondness for hurling missiles at shop windows as they passed by. Moments later, at least twice as many riot cops as there had been protestors thundered past, dressed like Robocop with visors, boots, helmets, perspex shields and drawn batons.
After which, it was judged safe to unlock the shop. 'Every Saturday,' said the teenager, with a pretty shrug. She meant that this was the 30th successive Saturday of a commercial district battened down against rampage, a 30th Saturday of diverted trams, cancelled markets, boarded-up banks, howling sirens, smashed cash dispensers, and shuttered small shops, cafes and restaurants, teetering on the brink of bankruptcy as their customers stayed at home.
But it turned out to be not quite the same as in past weeks. As we left, there came a fusillade of explosions from somewhere nearby, around the Place de la Comedie, the city's immense central square. An answering racket could be heard from the other direction, near the Gare St Roch, and a third from somewhere over by the Cathedral.
People, meanwhile, had stoically resumed their shopping and we joined them, winding up the slope to where the narrow street joins the Rue de la Loge, one of the main tributaries to the Comedie. It was then that we noticed a faint Guy Fawkes reek, followed swiftly by the sore throat. A billowing mist drifted through us. People pulled scarves and handkerchiefs to their faces, and scurried across the Rue de la Loge in the hope (not immediately realised) of cleaner air on its far side.
Glancing to our right we could see that the Comedie, 30 metres away, looked like (and was) a battlefield, wreathed in dove-grey smoke through which figures could be seen running forward to throw things, then retreating in the face of counter-attacks. It became impossible, in the fumes, to tell which side was which. There were loud reports, which I took to be police weapons discharging either gas or baton rounds. I learned later that there were two water cannons busy in the square.
It was, as the local paper Midi Libre reported next day, a game of chat et à la souris (cat-and-mouse) between the respective combatants – a new guerrilla warfare. Running skirmishes had replaced the usual big march grinding across town towards a set-piece confrontation. It was also, Midi Libre said, the product of a decision taken far away to designate Montpellier as that day’s focus of national action. Delegations had shipped in from Alsace, Lyon and Nice. And it had duly tourné au désastre, with around 20 arrests and a similar number of people injured, including 11 cops. Not to mention dozens, probably more, of parched, croaking, weeping bystanders.
If destructive mayhem has become its own end for the protests, then those leading them will have counted the day a success. Montpellier woke to another Sunday of sweeping up broken glass, unscrewing chipboard panels from window frames, and scraping sprayed slogans off belle époque buildings. Yet, paradoxically, there is now a tangible aura of defeat about the whole insurrection.
These were the late throes of an astonishing movement that once gripped the imagination of middle-France, but that has now abandoned any pretence of coherent policy, or of preserving the wide support it formerly attracted. What's left is a core of agitators, indifferent to public opinion or political impact, and representing nothing more articulate than the brick-brained bluster against the politics of reason that has been made lumpenly fashionable by Donald Trump and Brexit.
This is one of several ironies that surround a protest which began with a plausible desire to protect la vraie France against President Macron's business-friendly Atlanticism. It may still compare itself with the Sorbonne in 1968, but its real bedfellows are the baseball caps of the American rustbelt.
Besides, what sort of 'popular' movement goes out of its way to inconvenience and frighten the populace? One is forced to the suspicion that many of those hurling themselves at the riot shields every Saturday are now driven more by lust for battle than by any political critique, like the adolescent street gangs who agree appointments with each other for a knife-fight.
Meanwhile, grown-up politics have moved on. Neither Marine Le Pen nor any of the other parties hoping to hitch a ride on gilets jaunes' populism achieved the breakthrough they hoped for at the European elections. Macron has been swift to seize the advantage. On 12 June he sent his prime minister, Édouard Philippe, to parliament to announce the next phase of his economic reforms.
The branding is more thoughtful, the language more emollient, since the protests and the 'Great National Debate' that they provoked. But this was all about regaining momentum, not changing tack. Philippe promised a busy programme of tax cuts, back-to-work incentives, diminishing benefits, later retirements and renewed climate change initiatives ahead of the next presidential election three years hence.
It will be handled more sensitively than before, but handled nonetheless. What Macron intends to do is less significant than his conviction now that he can get it done. He has clearly concluded that the protestors no longer present a credible threat. Not that this is likely to deter the hard core of diehards from continuing to give people a pain in the back of the throat… and in other places too.