It was the tipping point of the financial crash. Leading bankers were locked in talks with the then Chancellor of the Exchequer. No agreement had been reached and the negotiations were lasting into the night. Then Alistair Darling said, ‘I am going to bed at one o’clock.’ And he did.

The world economy was teetering and he went to bed? It must have seemed like lunacy to the others around the table, a very un-macho move in the most macho of worlds. But it was a very intelligent thing to do, as we now know.

The bankers had blown the system. The Chancellor needed to mend it and that required a well-rested brain. A deal was done and the rest is history.

The UK Government is now so aware of the importance of sleep that it is launching a campaign urging the middle-aged to spend longer in bed. As a health benefit, sleep is taking its place alongside stopping smoking, improving diet and taking exercise.

It sounds bizarre, counter to our long-hours culture. We boast about being a 24-hour society. We work hard and play hard. Our cities never sleep. The ambitious amongst us have bought into being first into the workplace and last to leave.

Should employers now encourage them to think again?

The reason for the Government’s unusual edict is couched in health terms but, with the Treasury looking for savings, isn’t there another motive: money? Research is linking lack of sleep to a plethora of expensive problems.

Sleeplessness depletes our brain function. Our processing speed is slower, our memory is poorer and our judgment is impaired. We have raised stress hormones. These can raise blood pressure and increase stroke risk. Those who average six hours sleep are 12 per cent more likely to die before they are 65 than those who sleep for eight.

Sleep deprivation can also be dangerous, leading to accidental micro-sleeps. Tiredness can kill, according to the road safety slogan. As anyone who has been exhausted can testify, it also impairs empathy and reduces our ability to handle relationships.

As if all of that wasn’t convincing enough, research demonstrates links to obesity, heart disease and diabetes. These are three of the biggest financial drains on the NHS.

But why are we surprised?

In 2004 Charles Czeisler, director of sleep medicine at Harvard Medical School, published a series of reports on studies he’d conducted with 2,700 first-year medical students who were working 30 hour shifts, sometimes twice a week. He found that one in five admitted to a fatigue-related mistake that injured a patient. One in 20 acknowledged a mistake that led to a death.

Two years later, Mr Czeisler wrote in Harvard Business Review that going without sleep for 24 hours or getting only five hours sleep a night for a week is equivalent to a blood alcohol level of 0.1 percent (above this level we can experience slurred speech, impaired reflexes, even staggering). Yet modern business ethic celebrates such feats of endurance. "We would never say," Mr Czeisler commented, ‘“This person is a great worker. He’s drunk all the time.”’

But didn’t we know this even before Mr Czeisler and before the recent research? Haven’t we always known sleep is essential? If you don’t agree, look around your home. Some families live without a table to eat at. But show me the one that doesn’t have bedrooms.

They often take up more space than our living rooms. It’s hardly surprising since we spend one third of our lives asleep.

At least that’s what nature intended.

It’s the way we always lived until the 1980s. Back then it was rude to telephone someone before 9am. I still think someone is dead when the phone goes before 8am. It doesn’t happen often but when it does it’s usually a high-powered friend already en-route to an airport or a meeting.

The rational response would be to hang up or tell them to get a life. Instead I snap to attention, shedding the duvet as I grapple to find my wits, instantly riddled with self-criticism for somehow falling short of their driven ideal.

What am I thinking? It’s their actions that are unhealthy and irrational, not mine, but they’re catching.

Sleep is familiar to us yet, for all the research conducted, it remains a mysterious commodity. We spend part of it in deep unconsciousness which seems to aid memory and part in REM sleep when our brains are active but our voluntary muscles are paralysed. Brain scans suggest that we re-run the actions of the day as if committing them to memory.

According to National Geographic, all mammals and birds sleep. A dolphin sleeps with half its brain awake and when mallard ducks sleep in a line, the two outermost birds keep half their brain alert and one eye open to guard against predators.

Sleep is an integral part of our programming. So why have we allowed ourselves to be suckered into a lifestyle that prizes endurance working over what is natural? We are an exhausted society. Why?

Well, isn’t it about money again?

We work long hours because our jobs demand it and we need the jobs for our families.

Sleep isn’t valued because sleep is free. Isn’t that why we have heard so little about it until now? Isn’t it surfacing as a newly prized necessity only because the lack of it is proving costly?

Sleep deprivation causes poor productivity so sleep becomes necessary in the interest of profits. As can now be factually demonstrated, it leads to disease and life-threatening conditions and each of these carries a hefty price tag.

Sleep has been a Cinderella but can no longer be ignored.

Diet has a financial spin off in a multi-million industry. Exercise has spawned gyms and classes and fitness trainers. But sleep? There has been no profit in sleep. In our consumer society, it has been seen as time wasted.

Now there is a new challenge. Telling someone to sleep more doesn’t mean they will. In 2011, there were 15.3 million NHS prescriptions for sleep medication in the UK.

We must hope that a shift in society’s attitude will help. For 30 years – ever since Mrs Thatcher famously got by on four hours a night plus cat naps – there has been an insidious notion that sleep has been for losers. For wimps. Never mind the detrimental impact that such a culture had on family life.

Now we must hope that employers get the message that being well-rested equals being healthier and more productive. Will the pendulum swing back? If reason prevails it must. So much of our focus nowadays is on wellbeing and how to achieve it. Usually that means adopting a new exercise regime or diet or philosophy. For most of us sleep will be more effective.