No one alive has worked in the City longer than David Buik. He tells Ali Lyon what’s changed since his first day in September 1962, and what, mercifully, has remained the same.

It is 12:30 on a mild Tuesday afternoon, and as he takes to the blue leather stool and peruses his paper menu, David Buik is exactly where he is meant to be.

The City grandee can’t recall the exact number of times he’s frequented Mansion House’s Sweetings restaurant, but the historic Victorian-era eatery – best known for its inviting, anachronistic menu and equally inviting, anachronistic interiors – is a lunch destination of which the financial veteran of 64 years heartily approves.

“There have been a lot of really great restaurants in the City over the years, but Sweetings is…” his voice trails off, and his face scrunches up into a grimace of approval. “It’s the best.”

Our choice of Square Mile haunt is also sound given the backstory of the man I am here to meet. Sweetings has endured, essentially unchanged, for nearly 140 years. It survived two world wars, six owners, and the erection and demolition of skyscrapers – not to mention the coming and going of their speculative occupants. And while Buik’s own City career, which spanned the worlds of money broking, derivatives broking, financial PR and media commentary, may not have quite stretched over a century, he has stalked the City’s cobbled streets for well over half of one.

From ‘abysmal’ A Levels to a career in the City

The 82-year-old secured his first job in the financial district – straight out of school after an “abysmal set of A Level results” – in 1962, and since that first gig as a bank clerk, has borne witness to each of the City’s booms and busts, developments and regressions, from a front-row seat. There was rampant inflation of the 1970s, the abolition of exchange controls in 1979 – the “biggest change of my entire career”, the 2008 financial crisis and – of course – Margaret Thatcher’s ‘Big Bang’, whose 40th anniversary was celebrated by many City folk of Buik’s vintage last week. And be it City Index, Prebon Yamane, Cantor Index or Panmure Gordon, Buik has also outlasted many of the institutions where he once plied his trade.

Now, over six decades since first stepping into the Moorgate office of Philip Hill, Higginson, Erlanger, Buik has chronicled his vast professional adventures in a book: Money Markets Mayhem.

“I am just one of those really fortunate people who, as a person of modest ability, had a wonderful job,” he says after being asked why he took on the Herculean task of documenting such a varied and storied career. “And I don’t know anybody else – I don’t think – who’s worked here for longer.”

The world that Buik first entered on 17 September 1962 was a galaxy away from the Mansion House that we are both looking out on over a glass of white burgundy. Now, in the large office across from us, there are poorly-attended desks with four monitors each and conference rooms boasting vast projectors for the day’s international video calls. There are professionals hurriedly marching to their pit-stop of choice, destined – heaven forbid – to return, paper bag in hand, to eat at their desk. And – to Buik’s evident dismay – there is not a single suit and tie to be seen.

By contrast, on Buik’s first day at Philip Hill, Higginson, Erlanger, his manager gave him his marching orders for having the temerity to turn up in a “pale-blue shirt, collar attached and a plain dark-blue tie”.

“The office manager – a fierce Scotsman who had lost a leg on the Somme in World War I, looked at me sternly over his spectacles and asked me, in a thick broad Glaswegian accent, whether I was in the habit of coming to work in my pyjamas,” he writes. “I was sent home to dress appropriately.”

‘What people miss in the City now is the fun’

The salaries are just a shade different, too. Buik’s first monthly paycheck was the princely sum of £39 17s 6d, which now, according to the Bank of England’s inflation checker, would be a smidge under £780 a month. And as opposed to the sorry-looking sandwiches or sushi which today’s execs are hurriedly scoffing, the then-trainee would take his 3s lunch voucher (15p in today’s money) to the Sterling Castle for a steak and kidney pudding, chips and half-pint of bitter.

Appropriately, given our setting, it is this last difference about which Buik appears most exercised. The long City lunch, he says, is a fine tradition that has gone back decades. It produces serendipitous conversations, cultivates relationships, and is both fruitful and – crucially – enjoyable. But it is also, my interviewee fears, endangered.

“I think what people miss now is the fun,” he says, a hearty fish pie immediately before him, and a sea of Pret baguettes and salads beyond the window outside. “I recently went to a Japanese restaurant in the West End with an old friend from Barclays, and was sitting on a table next door to a broker and hedge fund manager. Apart from saying hello to one another they barely exchanged a single word: they were just on their phones.

“I, on the other hand, was out to lunch at least three times a week, and would either go to the opera or ballet at least once.”

Aside from execs’ increasingly subsistent relationship with food, Buik’s other great bete noire of contemporary life is the predominance of technology. Over our hour-and-a-half-long conversation, he grabs my phone three times as a prop for anecdotes to which the device was a pejorative punchline, and he is concerned about the impact it will have on his grandchildren’s livelihoods. “The thing that worries me – or upsets me – more than anything else is what technology is doing. These damned things – it’s an epidemic.”

But to paint Buik as a nostalgic luddite would be to do a disservice to a man whose nuanced, acerbic financial insights made him one of the most recognised financial commentators of any generation. Regular turns on the BBC, LBC and in newspapers including this one helped boost his and the City’s profile – eventually earning him an MBE for services to finance. And his unashamedly pro-enterprise worldview has even helped him amass more than 55,000 followers on the very social media platforms about which he has so many misgivings.

To the veteran, there are many areas in which the Square Mile is just as good or indeed better than the early stages of his career. “It’s less closed off and cosseted than it was, which is certainly a good thing. And in the world of derivatives, foreign exchange, insurance, professional services, we’re still number one.”

‘My number one passion is people’

That pride is part of the reason why Buik chose to put pen to paper on his memoir. For all its financial and cultural heft, the City is not, he says, given the credit it deserves in the wider firmament: something which he hopes, by steering clear of “sex and drugs” or “greed and excess” to correct.

“I’m so tired of hearing people vilifying the City, slagging it off, and giving it a really hard time. We need to consider that – together with the rest of the financial sector – it contributes £100bn to the Exchequer. And I just find it irritating that people don’t.”

The book offers no shortage of characteristically eccentric anecdotes, too. There’s the one where, during a stint in Tokyo, he could not understand why, despite lathering himself in aftershave, the locals avoided sitting next to him on the tube. A colleague duly informed him that he – like every western visitor – smelled of dairy and was thus unobliging company on a jam-packed tube. And there’s the time when, ahead of asking the parents of his first wife for their permission to marry her, he indulged in a six-bottle lunch with a colleague – only to fall asleep in an ice-cold bath to be woken up at 9pm by a call from his affianced, asking where he was. “Ali, I was smashed,” he remembers. “I could have died of hypothermia had that phone not gone off.”

But for all the fun memories, and the cheerleading and championing of what was his spiritual home for over six decades, Money Market Mayhem is, deep down, a book about people. Its 300 pages could act as a Who’s Who of the great, good, and some not so good, of British finance. Its castlist brims with household names like Robert Maxwell, Alastair Campbell and Lord Spencer, whom he describes as “by far” the biggest influence on his career. Graham Sounness – the former Liverpool player and manager – also crops up, as does the comedian Rory Bremner,  who is quoted on the book sleeve and who, Buik says, does a “wicked” impersonation of his unapologetic received pronunciation.

“I have four real loves in life: I love my career, I love horse racing, I love my family, but above all, I love people – it’s part of the reason I was such a lousy manager – I could never lay anyone off.”

The irrepressibly courteous Buik is on what must be his eighth “he’s just a lovely man” of the meal as he thanks our waitress profusely for the “delicious” fayre. And I am reminded of Buik’s tonic to life; one that helped him survive longer at the front line of UK finance than anyone else alive.

“I have always attached great credence to food,” he writes. “Good company, revelry, humour, gossip and great ‘craic’, supplemented with tasty food and above-average wine, go to make the greatest hobby of all time.”

I saunter off, immediately consulting my phone and anxious to return to my desk’s multi-screen set-up. And I leave Buik, and Sweetings, to remain exactly as they are.

Money Markets Mayhem, by David Buik, is out now and .