This was a particularly important revelation.

It combined drinking, complaining, and impractical shoes – which are not my three favourite things, though I know you're expecting me to make that joke.

The scene was thus: our favourite local, a jukebox joint in Highgate part-owned by Shane McGowan (so, naturally, one's liver is more or less doomed from the off), on a buzzing Sunday night.

A band was playing, the liquor was flowing, and the assembled masses were happily occupied trying to remember what the rest of the Pogues looked like, in case any of them should happen to pop in.

Flatmate and I, meanwhile, were berating ourselves for mistakenly choosing "sitting shoes" on what was clearly going to be a night of standing, possibly even bopping.

It's a forgivable mistake, as sitting shoes are generally the unfortunate combination of beauty, costliness and pain that so rarely gets a look in on the social radar.

Even in the life of people who text each other from adjacent rooms to save the walk.

But sitting shoes they were, and after several hours there was still not a seat in the place to relieve us.

Then, oh wonder of wonders, the three blokes on the sofa in front of us, get up and trot outside for a fag.

A vast plain of bottom-moulding, sitting-shoe-friendly distressed leather stretches out before us like the field of dreams. Sweet relief!

We may enjoy our evening from the lowered eyeline it has clearly been designed to accommodate! Victory!

But hang on a cotton-picking second – they've left their pints behind. Fiends!

And so the dilemma arises, its spectre looming like the ugly head of polite social etiquette between us and a night of sofa-based comfort.

We're good kids. We know the rules. We were raised according to time-honoured playground law, the codes governing lurgies and BFFs and hula hoop distribution ingrained on our psyche through years of cloakroom politics and sleepover ostracism.

So we all know that the universal allowance regarding seat stealing is three seconds.

This marginal window of time is stringent but fair, leaving the reckless occupant just enough time to grab the remote or retrieve a fallen Malteser before surrendering their throne to they who can most effectively rugby tackle them at the ankles.

Matters become more complicated when the involved parties are no longer eight years old and the wiley tricksters have left three full drinks behind.

And they are smokers.

Smokers now exist in their own chapter of the social rulebook. It's delicate territory – smoker-bashing is very bad form.

I'm not sure anyone expected the ban to have such hasty effect, but suddenly smokers are akin to lepers, vegans and people who wear flip flops in January.

They need sympathy and special arrangements.

And, as I have now discovered, they have created a whole new area of pub politics for non-smokers to negotiate.

To hijack the sofa felt like an awful, smug violation of human rights.

And yet, to placidly stand by, feet throbbing, while the tobacco troupe expect their seats guarded and preserved in the shape of their personage, seems like an ironic victory for the cancer stick.

All this is irrelevant, as while we stood around pondering the manners minefield and weighing up arguments from both sides of the sofa divide, some other scamp barged past and claimed it as his own anyway.

But next time, we'll be prepared.

We'll know our stance. Or we'll just wear standing shoes and save a lot of bother.