Two decades ago look like a golden age. The 1990s were the years between the fall of the Berlin Wall and the destruction of the twin towers: the age of the brief flickering of liberal optimism.

In the United Kingdom, there was Britpop, the peace settlement in Northern Ireland and the birth of New Labour. England’s football team even reached the semi-finals in two international tournaments, even if it lost both to Germany on penalties.

Things might not quite have been perfect, but they were better back then.

It is easy to be wistful for this bygone age. We certainly do not like what has come since: a survey by YouGov in 2015, before the fatalism that engulfed many in 2016, found only 7 per cent thought that life in the UK was getting better.

Yet nostalgia blinds us to the flaws of the Nineties: a time when Britain was more dangerous, more poverty-stricken and less tolerant than today. Forgetting this, we also forget the huge strides that the nation has made since.

Johan Norberg’s new book, Progress: Ten Reasons to Look Forward to the Future, charts the huge advances made by humanity globally in recent decades. And, by almost every metric, Britain too has made huge improvements in the past two decades.

Britain’s economy still feels in a state of profound crisis. Yet while the recession and its legacy have been disastrous, overall the economy is in far better shape than 20 years ago. After housing costs, the median income is 45 per cent higher now than in 1994, and the median pensioners’ income is 82 per cent higher, according to the Institute of Fiscal Studies. As a result of earning more, and the explosion in low-cost travel, Brits take 50 per cent more holidays abroad than two decades ago.

The most vulnerable in society have made many gains. The proportion of the UK population in absolute poverty, after housing costs, has fallen by one-third since 1997. The number of people in extreme low pay has fallen from 1.6 million to 500,000 since 1996, according to the Resolution Foundation. And the proportion of children growing up in households where no one works has almost halved.

Pensioners have particularly benefited in recent decades. If some now argue that pensioners are cosseted compared to other groups, few dispute that, two decades ago, many pensioners were treated appallingly. In 1997, 45 per cent of pensioners were in absolute poverty. Today, just 13 per cent are. The reduction in pensioner poverty, ensuring dignity in old age, has been one of the great policy successes of the last two decades, and helped life expectancy in England and Wales increase by five years since the 1990s.

Young people might not recognise as much, but there have also been huge improvements in the lives of youngsters too, beginning from birth. Infant mortality has fallen by 40 per cent in England and Wales in the last two decades, and is now at a record low. After housing costs, there has been a 40 per cent decrease in child poverty since 1997.

Today’s young people are also far less likely to have their lives affected by alcohol, cigarettes or drugs than two decades ago: consumption of all these substances has fallen significantly among the young. Teenage pregnancy is also at its lowest rate since records began in England and Wales in 1969.

The ascent of the new young fogeys, as the New Statesman has called today’s clean-living youth, has many causes: not only the financial pressures faced by today’s young, but also their increased motivation and ambition, better parenting, and improvements in policing through schemes like Challenge 21 and Challenge 25 that curb underage drinking.

The smoking ban in workplaces and enclosed public places has also contributed to the proportion of adult smokers declining by one-third in the last two decades. The rise in good behaviour extends to children: only 8 per cent of 15-year-olds are regular smokers, compared to 28 per cent in 1994, and bunking off school has also fallen out of fashion.

Young people are not only better behaved; they are also better educated. “Access to early childhood education and care used to be poor by international standards, now it is virtually universal,” says Andreas Schleicher from the OECD.

The improvement in educational standards is most obvious in higher education. Young people are about a quarter more likely to go to university now than 20 years ago. The percentage of the most disadvantaged students at universities, including elite institutions, is also at a record high, showing how the improvements in education have not just been captured by the middle classes.

Domination of private schools at leading universities has, contrary to popular perception, actually been reduced. In Oxford University’s newest intake, 59.2 per cent of places were offered to pupils from state schools – the highest figure for at least 40 years. In 1995, only 48.1 per cent of Oxford students came from state schools.

Society is also far more tolerant than two decades ago. Civil partnerships only came into existence in 2004, and gay marriage was not introduced until 2013. Attitudinal change has been profound. In 1990, 58 per cent of people thought that sexual relations between two adults of the same sex were always wrong. By 2013, only 15 per cent did.

Racism, too, has declined. Despite the evidence of a rise in racist crime since the United Kingdom’s vote to leave the European Union, the long-run trends are altogether more positive. In 1996, 35 per cent of white people told the British Social Attitudes survey, carried out by NatCen, that they would mind a little or a lot if they or one of their relatives was married to a person of black or West Indian origin. By 2013, that figure had fallen by one-third, and the percentage of white people who said they would mind if one of their relatives married someone of Asian origin fell by a similar amount.

Greater levels of education are driving increased tolerance: graduates are half as likely as those without qualifications to say they feel racial prejudice.

Many immigrant groups have also assimilated into Britain with remarkable success. Consider Bangladeshis. Two decades ago, Bangladeshi children were among the worst-performing in Britain. Yet the results of Bangladeshis on Free School Meals improved more than any other ethnic group on FSMs in the last decade, and the improvements have been reflected in the world of work. The proportion of Bangladeshi women in work has risen by one-third in the last five years, according to Yaojun Li, from the University of Manchester. The ascent of Bangladeshis, in school and in work, serves as an antidote to those who say that multiculturalism can never work.

Progress has also been made in gender relations. In 1991, 33 per cent of people thought that “a husband's job is to earn money; a wife’s job is to look after the home and family”; by 2012, only 12 per cent did. The pay gap between men and women in the workplace has narrowed dramatically – indeed, women between 22 and 29 now earn an average of £1,100 more than men, reflecting how four women now go to university for every three men.

There are now a record number of female MPs, to go with the record number of ethnic minority MPs in the House of Commons.

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Rare is the day that passes without more headlines warning of the perils that Britain faces, both at home and abroad. And yet the country has never been safer.

Consider terrorism. Despite a recent spate of horrific terrorist attacks in Europe, Britain is far safer from terrorism than in the days when it was imperilled by the IRA. The number of people in the UK killed by terrorism in the last 15 years is lower than the average number who were killed by terrorists each year from 1968 to 2001.

But the real reason that Britons are far safer than two decades ago has nothing to do with terrorism. Overall crime has fallen by two-thirds since 1995. We forget that the mid-Nineties were not merely the age of Euro ‘96, but also the time when crime – including violent crime – soared to record highs in Britain.

In 1995, five in every 100 adults were a victim of violent crime in the last year; now, only two in every 100 adults are – a record low. The good news extends to the decrease in murder: there were 518 homicides in the year ending March 2015 in England and Wales, the lowest number for 32 years.

Perhaps the greatest reason for cheer is something that day-to-day headlines never address: how much safer Britain’s roads have become. In 1996, 3,598 people were killed in road accidents. By 2014, only 1,775 were. This steep reduction might just be the greatest advance in British life in the last two decades but, in keeping with the spirit of a gloomy age, we have not celebrated it at all.

Why, then, do we not feel any better than two decades ago? The media, and its endless tales of woe, is partly to blame, though it is merely exploiting human nature: bad news sells. That we remember what is bad owes to what the psychologists Daniel Kahneman and Amos Tversky called the “availability heuristic”. Humans remember bad news, from terrorist attacks to tales of teens behaving badly, most easily and so think that this bad news is more frequent than it really is. That is why society has always been in thrall to the notion that today is worse than yesterday, as Arthur Herman shows in his book The Idea of Decline in Western History.

Our pessimism not only belies the facts. It also profoundly impacts how we behave: those who were most pessimistic, and thought that society had deteriorated in recent years, were most likely to vote to leave the EU. Similarly, those most negative about recent changes in America were most likely to support Donald Trump.

Arguing for optimism is not to ignore the monumental challenges Britain faces. Rather, recognising the huge gains that Britain has made in recent years gives the nation the best chance of consolidating these in the coming years – and making life, in defiance of all the doom, better still.