Some high fliers retire in their 30’s. For many, the dream isn’t quite what they imagined.

Henry Smith lived a typical life, working his way up the corporate ladder. Straight out of university, he had found a contracting job in IT services in his hometown of Sydney, Australia. The money was good, but soon the mind-numbing work and long commutes took their toll. He desperately wanted a way out – and he found it in a dubious-looking finance blog called Mr Money Moustache.

The site assured retirement years ahead of the norm to those who could follow a set of principles set forth by its founder, self-styled finance sage Peter Adeney. With no desire to keep at his dull career for another four decades, Smith (whose name has been changed at his request) quit his £70,000-a-year full-time job in 2016 at the age of 31 with no plans to find another one and £400,000 in the bank.

Smith had joined the “Fire” movement. An acronym for “Financial Independence Retire Early”, it has become a large online community of young people intent on quitting work for good – as soon as possible – by following a specific game plan espoused by Fire bloggers and podcasters, who serve as the leaders of this cult. The main Fire subreddit has more than 500,000 followers, with discussions centring around the core method: first, save 50 per cent or more of your earnings – far more than any regular financial advisor would recommend – using a set of extreme life hacks. The next stage is to deploy the Fire gurus’ special investment strategies in order to generate a passive income that’s sufficient to support your lifestyle in perpetuity. Think of it as the minimalism movement meets Squawk Box.

On specialist forums, Fire enthusiasts evangelise about their new lives: simple but manageable and free from the tyranny of work. In recent months, Fire has spread to the UK and enjoyed a surge of hype-fuelled interest from the mainstream, but some followers have discovered it’s not quite the silver bullet they were looking for.

IS HOARDING HALF YOUR INCOME IN SEARCH OF EARLY RETIREMENT REALLY WORTH IT?

Although Fire began as a frugality-inspired reaction to counter rabid consumerism, its dirty little secret is that it is only an option for high-income earners. The maths behind the movement works on a sliding scale – the higher your rate of saving, the quicker you can retire. It’s obviously difficult to maintain a high savings rate if a large chunk of your money is spent on essentials such as food and rent.

Tanja Hester, author of Work Optional, says she may have sacrificed too much in pursuit of early retirement, which she reached a few years ago at the age of 38. Her miserliness meant she passed up important experiences, including the chance to go to a friend’s wedding abroad with her boyfriend, even though it would have only set her retirement date back a month or so. “We were thinking of the money more than the life memory and supporting our friends,” she says, adding that she barely took holiday before quitting work. “That contributed to a feeling of being really burnt out.”

Even those who do hustle their way to Fire often discover that the lifestyle isn’t sustainable. Sam Dogen retired from his investment banking job in 2012 at the age of 34 to become a stay-at-home father while running his blog, Financial Samurai. Now, seeing a storm on the horizon for the economy, he is returning to work. “We don’t truly know our risk tolerance until we start losing a lot of money,” says Dogen, who is based in San Francisco. He lost nearly £240,000 on a property investment when house prices shrunk in the US at the end of last year, which shocked him into realising the precariousness of his situation.

There’s also a larger, existential problem – one familiar to retirees of all ages. Smith was now job-free, living off his investments and trading cryptocurrency, but it just wasn’t doing it for him. “In the beginning, it was the best decision ever,” he says. With no office to commute to his mornings felt brighter and he had freedom to enjoy the simple things – strolling to get coffee, chatting with strangers – that corporate life had obscured. “That freedom was a blessing,” he says. “But with time it turned into a curse that I wasn’t expecting at all.” Soon, he spent his lazy mornings chatting to the walls of his empty apartment. Loneliness crept in, then self-doubt and, finally, a bad break-up. “All these things crescendoed into a loss of identity.”

So, is hoarding half your income in search of early retirement really worth it? Perhaps retiring is the wrong way to look at it. Henry Smith is back at his old job now, but he still thinks that Fire was the right decision. “It’s the fact you don’t have to be a slave to the system if you decide not to,” he says. “I can walk away whenever I want.”