As a child, I was regularly warned to keep away from swans, because “they can break your arm”. Friends tell me they were given the same instructions. Why, then, aren’t the riverbanks littered with less cautious children, wailing and clutching their shattered limbs? It’s a lie, isn’t it?

Having your arm broken by a swan is, I reckon, about as likely as blowing up a petrol station by talking on your mobile phone. On an average day, how many mushroom clouds of black smoke do you see in the distance, as yet another Shell station explodes? Fewer than ten, I bet.