I felt the urge to pass this story on to you lot, not because it’s necessarily science fictional or futuristic (though it could be, in the hands of a good writer), but because I think it’s genuinely fascinating. The New York Times has an article about a young lady named Hannah Upp who went missing while out running in late August, only to reappear nearly three weeks later floating face-down (though still alive, barely) in New York Harbour.

Sure, people disappear all the time – what’s rare about Ms Upp’s disappearance is that she doesn’t remember any of it at all. It’s something that the psychologists call a dissociative fugue.

The medical condition diagnosed in Ms. Upp is so uncommon that few psychiatrists ever see it. Characterized in part by sudden and unexpected travel combined with an inability to recall one’s past, dissociative fugue demonstrates the glasslike fragility of memory and identity.

Its most famous sufferer is the fictional Jason Bourne, the secret agent made flesh on film by Matt Damon. The Bourne character takes his name from Ansel Bourne, a Rhode Island preacher who suffered the earliest recorded case of the condition when he was en route to Providence in 1887. The preacher continued to Norristown, Pa., where he opened a store and lived with another family, until one day he “woke up.”

The memory of how to perform mundane tasks like hailing a cab or even using the Internet remains intact. Victims lose only the memories tied to their identity.

A weird and fascinating tale, and a reminder that the human mind is something we only understand very poorly. The hat-tip goes to Tim Maly on Twitter, who we may well be hearing more from in the near future…