Some people leave Belfast for Dublin on the Twelfth of July. Last year, I made the journey in reverse. I was working there and had completely forgotten what day it was until I changed trains at Central Station and found myself in a carriage packed to the doors with people going to watch the main parade at Shaftesbury Square, or Lisburn Road.
The carriage smelled like a brewery and looked like a mobile off-licence. There were, in the words of the Christy Moore song, 'bottles, barrels, flagons, cans' stacked on and under the tables - supplies for the day ahead.
I don't think anybody was drunk - not a great boast; it wasn't noon yet - but there was a whole lot of drinking going on.
In the late afternoon, I passed some of the same people waiting with thousands of others for the return parade.
They had been hanging around for hours and the detritus of their outdoor party covered the footpaths in a carpet of broken glass and flattened aluminium.
There were still hours to go. Plenty of drinking-up time left. A supermarket on the Dublin Road had a separate queue for customers not buying alcohol.
When I looked, there were three people in it, two of them Chinese. The alcohol queue stretched halfway round the shop. Drink was flying off the shelves, which were emptied as fast as they were restocked.
Up past the City Hospital, where the crowds were a little thinner, every lamp-post had a selection of drink stashed around it. Ironically, many of these same lamp-posts carried notices warning of the penalty for drinking on the street.
Not everyone was drinking, of course. There were young families enjoying a good day out and other sober citizens who never touched a drop.
And, in fairness, I have to say that even the drunks were well-behaved. The atmosphere was light and cheerful, with friendly jibes exchanged between marchers and spectators and helpful explanations offered to visitors - a good few tourists were watching the parade.
At times, it was close to Orangefest, that elusive, inclusive carnival the Orange Order has been aiming for in recent years. But, as the bottles and cans got passed around, the carnival that came first to mind was the Munich Beer Festival. Vodka and Orangefest, perhaps?
Such alcohol consumption seems odd in followers of an organisation which once prided itself on advocating temperance. But it is very much in line with a remarkable change which has affected almost every aspect of our social life.
Temperance is a word which once loomed large in the Northern Ireland lexicon. There were temperance hotels, which didn't serve alcohol, and temperance associations, which held their annual meetings in temperance hotels and organised temperance outings, temperance parties and temperance weddings.
The Catholic Church's Pioneer Association was a powerful temperance body that politicians ignored at their peril and the wearing of a pioneer pin was a common declaration of teetotalism.
There were temperance Orange lodges. Still are. But where once they represented a significant body of opinion, embedded in the very marrow of the loyal orders, they have now been swept to the margins by the tide of alcohol that engulfs every event.
There was, to be sure, a good deal of hypocrisy about Northern Ireland's old anti-drink ethos. And there was always a lot of drinking around the Twelfth.
Indeed, the joke was that those temperance lodges would always be put at the head of the return parades, since they were the only ones who could find their way home. Nevertheless, Northern Ireland was once a society that tended to frown on drinking. It is not so very long since pubs closed at 10pm and didn't open at all on Sundays.
Few restaurants had drink licences. There were no bars at sporting events and entertainments, such as dances, were dry.
Now drink is an integral part of every fleadh and football match, every concert and family christening, every beach party and back-garden barbecue.
Secondary school students drink to celebrate the end of exams, then head off on sun holidays where drinking is the main event each night.
Bars are built into all-modern places of entertainment and sporting venues.
You can drink alcohol at the theatre and the cinema, while waiting for a train or travelling on one.
You can buy beer in a supermarket that is not much dearer than water and a lot cheaper than petrol.
Periodically, we beat ourselves up over some new report pin-pointing our high levels of binge drinking and alcohol dependency.
A survey produced for the Department of Health early this year found that almost one-in-10 people in Northern Ireland has a drink problem, with excess drinking worst in the 18-to-29 age group.
We profess to be shocked by such statistics. But how can we be? We are a society in which a large number of people believe it is proper to start drinking in the morning, while transporting copious amounts of alcohol to consume as they watch the parade of an organisation which advocates temperance.
The only surprise is that the number with drink problems is as low as one-in-10.
What percentage, I wonder, lies to people conducting health surveys?