I’ve been listening to the audiobook of Bill Bryson’s excellent “The Life and Times of the Thunderbolt Kid”, his autobiographical account of his early life in Iowa.

It’s as funny, charming and wistful as you would expect, full of fantastic imagery of post-World War II consumerism, invention and prosperity. And, of course, it harks back to the innocence of a childhood utopia that probably didn’t actually exist.

But what struck me with the most force was the sheer optimism of the time. Even with the constant threat of nuclear obliteration, with memories of the war still vivid in most adults’ heads, most US citizens seemed to believe the future was brighter than the past. Their country was the wealthiest, the most powerful and, yes, the happiest on the face of the planet. National leaders were respected and even liked (as in Ike). In a pre-Watergate era, politicians, though viewed through a healthy filter of cynicism, were nevertheless acknowledged as local and national leaders, essential to the workings of a democracy that, having been fought for only recently, was still precious.

So where did it all go wrong? In our own country today, despite the recent credit squeeze, our citizens have never been so wealthy. High-def TVs fly off the shelves at Tesco quicker than they can be imported. Whatever the latest technological innovation, most people can treat themselves to it. Eating out – a rare treat when I was a child in the ’70s – is as commonplace as going shopping. And when we do go shopping, whether for groceries or for clothes, we spend money in quantities that would have made our parents gasp.

We’re securer than ever, at least in international terms. There’s no equivalent of the Soviet Union threatening to bury is in a nuclear armageddon. The very real threat of terrorism hasn’t notably altered anyone’s patterns of behaviour or travel (which is as it should be). Job security is felt to be less than in the past, it’s true, but the corollary of that is the tremendous real-terms rises in incomes over the years and the consequent improvements in quality of life.

There are more two-car homes in Britain today than there are homes without a car at all. We live longer, eat healthier (if we choose), have better access to forms of entertainment never imagined a generation ago (satellite TV, DVD, computer games), the majority of us have fast access to the worldwide web, which we use to enable even more spending and for entertainment. Crime is down.

So why is everyone so bloody miserable?

Are our crippling levels of cynicism and pessimism simply part of the human condition? Were we always like this? Or is a consequence of the “instant gratification society” that, having been instantly gratified, we must resent the society that manipulates our desires in this way?

I will, on this one occasion, concede that the mass media can’t be held entirely to blame, just as I hope readers of this blog will accept that our elected leaders are similarly not 100 per cent guilty.

But what happened to that post-war optimism and commitment to common values? Are they gone forever and if so, why? If not, how can we bring them back?

Heavey stuff, I know, but occasionally you want to talk about more than the latest episode of Doctor Who.