I am hardly one to look for life lessons in movies or works of fiction. Occasionally, though, every rule has its exception, though, and mine is A Beautiful Mind. Beautiful Mind comes to mind, pun intended.

The film follows John Nash, a brilliant mathematician whose ability to recognise patterns helps him make sense of problems that leave other people bewildered. In the film, he believes he has been recruited to uncover secret Soviet messages hidden in newspapers and magazines. He finds connections, deciphers what he believes are codes, and assembles a convincing explanation. For a good stretch of the film we believe him as completely as he believes himself.

We follow those connections with him. Then we discover that the secret assignment and some of the people involved are products of his illness. His mathematical brilliance is real, the conspiracy he believes he has uncovered belongs to the world his mind has constructed.

The instructive part is how convincing a story can become when all its pieces appear to fit.

John’s mind did nothing unusual, in fact it did what every mind does, only more of it. Our minds are uncomfortable with gaps. We want events to have reasons, behaviour to have motives, and endings to make sense. In fact recognising patterns is part of how we learn and survive. Our forefathers watched the sky, the ants, the birds and the heat that comes before the rain, and they planted accordingly, that habit fed generations.

That ability serves us well, however, it also gives us the means to construct a pattern around an explanation we already favour.

A few days ago, news came of a prominent figure dying in a helicopter crash. The rumour mill as always promptly went into overdrive. People began revisiting his words, his movements and his generosity, searching for signs that he knew what was coming.

A gift becomes a farewell. A visit becomes a search for spiritual protection. An ordinary remark acquires the weight of a prophecy.

Once we know how a story ends, it becomes remarkably easy to read the ending into everything that preceded it.

Those who came before us had an expression: Ukatsvaka makudo mugomo unoawana. If you go looking for baboons in the mountain, you will find them. I have always heard cautionary tale in those words. What we set out to find can shape what we notice, what we collect and what we consider meaningful.

If we begin with the conviction that a man foresaw his death, we can gather moments that appear to support it. We can focus on a cluster of gifts, visits or statements and build an explanation around them. The rest of his life quietly falls out of the frame.

I think the context is found in the whole, the wider timeline matters. Was the generosity new? Had he behaved similarly for years? What did people make of those same actions while he was alive? Would we have read them as farewells if he had lived another twenty years?

Those questions help us judge how much of the pattern belonged to his life and how much we have supplied after his death.

I think sudden death creates a particular hunger for explanation. Someone was here, making plans and occupying space in the world, and then they were gone. A story about foreknowledge gives that rupture a kind of order. It suggests that somewhere, beneath the shock, the ending was already understood.

I can appreciate the comfort in that. I also think comfort asks something different of a story than evidence does.

Nash’s illness is specific to his story. The lesson I draw from the film concerns the confidence a coherent explanation can inspire. We tend to treat certainty as the reward of a good mind, the place thinking is meant to arrive. Nash’s illness suggests the opposite. His mind arrived too easily. It closed every gap, answered every question, and left him nothing to wonder about. The healthy mind, it turns out, is the one that can leave a question open and still sleep at night.

The poet Keats had a name for this. He called it negative capability: the ability to remain in uncertainty and doubt without reaching irritably after fact and reason. He thought it was the mark of a great writer. I have come to think it is the mark of a sane citizen. A rumour is what happens when a whole community reaches irritably at once.

Perhaps this is the deeper meaning of the proverb. The baboons on the mountain tell us very little about the mountain. They tell us a great deal about the one who went looking. Every explanation I find convincing is, in part, a portrait of my own fears and loyalties. So before I ask what happened to the man in the helicopter, I ought to ask what I wanted to have happened, and why.

A gap in our knowledge is uncomfortable, but it is honest. It is the space where the truth has room to arrive on its own terms. The forefathers who read the sky knew to watch carefully for the rain, and leave the clouds to speak for themselves.