I have two favourite Bletchley Park stories. One was of a rounders match played between the British codebreakers and the Americans who'd joined them after Pearl Harbour. Rules were agreed, the game was played, and at the end, both sides thought they'd won. This seems to me to say something quite profound about this country's relationship with the United States.
The other concerns Alan Turing, the most brilliant of them all, who committed suicide in 1954, two years after he'd been arrested for homosexuality - as the film director Michael Powell said, Britain doesn't treat its heroes very well. A codebreaker interviewed years after the war observed that talking to Turing made him realise the difference between intelligence and genius. Talking to a very intelligent person, you hear ideas that you (possibly) could have come up with yourself, if you'd only had the time. Talking to a genius, like Turing, you hear ideas that you know you never would have had in a million years.
Since hearing that, I've used it as a personal shorthand for a genuinely astonishing idea - one that I know I could never have come up with myself. I'm not a scientist, so my Turing moments are mostly to do with writing - lines, ideas or images that come from a place I've never been, and never will. Offhand, I can think of a few; the description of the fog at the start of Bleak House, the last line of Some Like It Hot (written, according to I.A.L. Diamond, at the end of an exceptionally heavy day, and intended as a placeholder until they could come up with something better), and Smokey Robinson's realisation that, in large enough quantities, the salt water of tears can leave a track.
Inevitably enough, the writer who's passed my personal Turing test most often has been William Shakespeare, the person for whom, according to Jonathan Bate, the concept of genius was invented. His very familiarity sometimes makes this hard to spot- so many of his phrases are stuck in the language that we forget how genuinely bizarre they are. A trivial example will do; Cleopatra's 'my salad days, when I was green in judgement'. How many of us, if we'd never heard it before, can honestly say that we would have come up a woman who describes her youth by comparing herself to a lettuce?