Why are we so hungry for bad news? Why do we spend so much time contemplating one moment of horror and so little time thinking about what is right with the world?
Fear is entangled in our DNA. The tribe with high levels of anxiety, perpetually scanning the horizon for signs of trouble, was more likely to survive. Many thousands of generations later, we stare at a car crash with a mixture of pity and empathy, together with an urge to avoid the same fate.
When Alfred Hitchcock was asked, ''How long can you show a couple kissing on a bed?'', his answer was: ''As long as you like, providing there's a bomb ticking under it.'' In other words, fear is an easy emotion to arouse and then maintain.
Fear may be useful, but it can also produce self-fulfilling prophesies. Fear of crime, however unjustified, makes people avoid walking the streets at night, creating neighbourhood streets that really are less safe. Fear of an economic downturn means we stop spending, which then causes the very economic downturn we feared.
When people say ''count your blessings'', or invite you to hum along to ''accentuate the positive'', it can sound inane - a turning away from the world and its problems. Yet sometimes those problems grow larger because of thinking that is too negative, too fear-filled, too pessimistic.
Here's my point: there's nothing soft-minded about ''counting your blessings''.
Contemplating the good in the world is part of giving yourself an accurate grip on reality. This, in turn, is the only way to make good decisions and live a contented, successful life.
We shouldn't be shy about demanding a mix of news that is both good and bad. We also shouldn't fall for the idea that grim news is somehow more rigorous, or truthful, or serious, than news that captures the world in all its richness. (The same, incidentally, is true in the world of literature and film where ''the grimmer the better'' has become one of the more fatuous calling cards of our age).
So, let's say it out loud. We live a third longer than 50 years ago. Famine is much less common. In the fight against malaria, the humans are winning.
It's far, far better to be gay than was once the case. Sydney's air pollution is much lower than it was a generation ago. We decided to stop building our homes from asbestos sheeting.
And let's also give thanks to the Blessings of Small Things:
Most stains come out in the wash.
Snow falls on mountains, which are perfectly shaped for skiing.
The best-tasting drink in the world - water - is also the cheapest.
Deciduous trees grow leaves, and make shade, at just the right time of year.
Socks are designed to fit either the left foot or the right.
A beer tastes best after hard work.
And the more in love with someone you are, the better looking they become.
Actually, you know, it's a wonderful world.
“This is the only advice I offer you. Pick the small thing, and carry it on. Let it change your life.”