Optimism, when you think about it, is a wonderful and surprising attribute to find in the human mind. It can beat the ability to reason which, we think, distinguishes us from the rest of animal life. I ponder this sometimes - not often - in the sea.
Optimism is such a blessing that if the thought of a shark occurs to me in the water, the thought passes, as it obviously does for everybody who enjoys a swim. It doesn't haunt us as, rationally, it could. There must be hundreds of sharks out there at any time and the way they range, well ... What are the odds?
A lifeguard at Papamoa, where a bronze whaler nosed in among swimmers on Tuesday, said a sighting is a daily occurrence. I can believe it. Unless a shark puts a fin above the surface nobody in the surf might notice. The Herald in 2011 featured an aerial photo of a beach with ominous shapes inside the breakers where bathers were oblivious to them.
Sharks are by no means the only risk almost everybody can face but the others are balanced by a rational need. The risk of meeting a speeding car head-on is outweighed by the benefits of using the road. The attractions of travelling a long way in a short time can overcome most people's fear of flying.
But we have absolutely no need to go into the sea. We defy the risks for sheer pleasure. We laugh at rationality. We respond in a spirit that simply says life must not be diminished by fear. We will take the chance for fun. We are capable of glorious optimism where our own welfare is concerned but not when we have to make a decision carrying the slightest of risks for the public.
Just a block behind my nearest beach stands a red-brick church and steeple that gives some charm to a neighbourhood of otherwise undistinguished real estate. I wrote about it last summer, going so far as to claim the church gives the bay a bucolic character as though it was on the real East Coast, not Auckland's.
It was, I suggested, an example of the needless damage that could be done to communities throughout the country if we overreact to the Christchurch earthquake.
Well, it has happened.
The church has been closed. A notice on its door is headed, "Warning - Earthquake Risk". An initial structural evaluation report, it explains, indicates the building is "earthquake prone" and has been rated at 24 per cent of the new building standard.
"Anyone entering this building does so at their own risk," it warns, which would be fine if people could still enter. I am sure most people would consider the information for a moment and decide the chances of an earthquake occurring in the Auckland region during their lifetime are negligible.
I am equally sure the good people of the parish who have closed the church while they find out what needs to be done have no qualms about stepping inside either. But they are not prepared to take even a negligible risk with the safety of others.
The same can be said for the state government of Western Australia that has decided to hook and shoot sharks near its swimming beaches after a seventh fatality within three years. Protesters were not spooked by the shark attacks, nor probably were the decision makers as individuals. But glorious human optimism goes out the window when individuals find themselves with a social responsibility.
The chances that the church will be strengthened appear slim. It has been surplus to the parish's needs for years. It has been used for community meetings too, but even if every member of the community petitioned the parish committee to say they really didn't mind the risk, I doubt we could save it.
That personal risk assessment was called "optimistic bias" by the royal commission of inquiry into the Canterbury earthquakes when it recommended mandatory strengthening or destruction of all unreinforced masonry buildings that do not meet the code.
Our optimism relies on many others being also at risk. It is comforting at a beach to know that if a passing shark feels like a leg for lunch he has a choice of many besides mine. Somewhere in the Gulf this afternoon I'll dive off a boat fighting the idea that I might be only decent meal around. But the safety of numbers does not apply to the indiscriminate risk of earthquakes. Yet the destructive new code will apply only to public buildings. When it comes to the safety of private homes our natural optimism can prevail.