It was just after the morning school run when it happened. I was in Gail’s, standing behind the lady in the duffle coat and big red glasses, when I clearly heard the call “flat white” from behind the hiss of the La Marzocco. Forward I went to grab the paper cup from the counter — only to feel the heat of half a dozen pairs of eyes trained upon me. “It’s not yours!” cracked a clipped verbal missile from the back of the line. “There’s a queue here!” piped up a short man in a tracksuit just behind me. The barista could only shrug pityingly. After what seemed like a lifetime, I slunk past my accusers, the correct flat white in hand. The ground could have swallowed me up.

On the way home, I began to reflect on other situations where my behaviour had come into conflict with the new social norms being practised all around me. There was that time during the summer, for instance, when I berated a fellow beach goer for the non-stop thudding coming from his beat box, which he had brought with him for the day along with a portable barbecue, only for the surrounding day trippers to look at me as if I were a high-ranking SS officer rounding up partisans. Then there was the afternoon I sat defiantly still at the cricket while all around me they were doing the “Mexican Wave” and booing anybody who didn’t join in the fun.

Manners are a minefield, aren’t they? One minute you’re supposed to be putting your fork down at a particular angle, and the next you’re meant to be making your neighbours feel at ease by standing bolt upright and waving your arms up and down as Joe Root attempts to reach his century.

In the stands at Lord’s, it felt uncomfortable enough, but at the coffee shop I felt like one of those poor sods in a classic HE Bateman “The Man Who…” cartoon from a pre-war edition of Punch or Tatler: the man who lit his cigar before the Royal toast…passed the port the wrong way…threw a snowball at St Moritz… and so on.

In those days, there was a high price to pay for non-conformity

In the former, the rather smug and well-heeled individual (obviously a nouveau riche upstart) is blowing smoke rings towards the dining room ceiling while his all-male dining companions and the liveried waiters behind are rendered speechless. The port passing offender is equally oblivious to the faux pas as a similar scene unfolds around him. This time the waiter launches a tray of cigars into the air in pure, abject horror.

Joking aside, social transgressions like these were often just around the corner for anyone mixing in snob-ridden upper and middle-class circles in the early 20th century. In those far off days, there was a high price to pay for non-conformity and getting it wrong. Ridicule was something to be scared of.

A hundred years later, with our seemingly more relaxed class and social structures, you’d expect there to be a more forgiving attitude to lapsed etiquette, when in fact there appear to be more ways than ever to elicit disapproval from our peers. This is rarely to do with where your dessert spoon is placed.

As we’ve said our last goodbyes to the concepts of deference and chivalry, we are left painfully short of the clear-cut behavioural guidelines we inherited from our parents: respect of authority, being kind to strangers, not boasting about yourself and not eating with your mouth open.

Online communication, social distancing guidelines and the so-called culture wars raging in our schools and workplaces have all helped to create a gap in the market for an entirely new set of rules. Isn’t it about time we well-meaning cosmopolitan types had it from a higher authority in the void left by elders, the church or the state? How does one respond, for instance to a guest dumping their iPhone in the centre of your kitchen table, or a grown adult sending you a line of emojis at the end of a WhatsApp message? Should you use gender-neutral pronouns at work? How many weeks must pass before you switch your blacked out Instagram profile, in support of the latest hashtag campaign, back to your regular head shot?

Nicky Haslam has been having some fun with our manners malaise

Meanwhile, in the real world, are you going to shake the boss’s hand at this year’s Christmas party? Or do you go with a “don’t you dare” wave or a cheeky fist or elbow bump? When it comes to more formal events, I guess we can still reliably call on Debrett’s, the “unrivalled guide to protocol and modern manners”. Need to know what sort of dickie bow passes muster at a smart black tie do, or how to address Princess Michael of Kent should you bump into her at Waitrose? Debrett’s have dealing with this kind of thing since 1769.

Personally, I believe Debrett’s are on a hiding to nothing in these phone-wielding, eye contact avoiding, individualistic age where fast food, fast fashion and fast dating rule, and McDonalds can get away with the ad campaign I Think We’re Alone Now. Watch as various self-satisfied customers (who it seems can’t actually be arsed to make the short trip to their nearest Golden Arches) shut themselves away from their nearest and dearest to shamelessly scoff Happy Meals. I mean, what hope do we have in getting our children to sit still and eat their vegetables, all while discussing the Northern Ireland Protocol?

Perhaps with a firm nod to Nancy Mitford’s famous 1954 essay on “U and non-U” English (vegetables vs greens, sitting room vs lounge etc), the interior designer, society figure and friend to the royals Nicky Haslam has been having some fun recently with our current manners malaise. Under the banner Things Nicky Haslam Finds “Common”, his set of expensive but hilarious tea towels are selling like hot cakes. “Self pity”, “eating early”, “having guests remove their shoes” and “baby showers” are just a few of the things that irritate the well-connected interior designer. Take note, Harry and Meghan.