Thousands of feet up, somewhere between space and earth, night seems to go on forever. For hours, a never-ending sunset has been doggedly following the plane, trailing its woolly strands of orange and purple like an exotic jellyfish. Only now as I press my nose against the perspex window do I see that we’ve finally left it behind. There is nothing out there any more – just a world so black and vast it makes me want to topple into it and disappear.

I check my watch: two a.m. English time. New Year’s Eve. Looking around at my fellow travellers, slack-jawed and mute with exhaustion, I wonder what will happen to us all in this year to come. Who on this plane will die? Who will become a grandparent, embezzle funds or burst into tears at their first grey hair? And the idea makes me unaccountably sad. What is it about flying that makes people so hopelessly sentimental? Something to do with the lack of air, I suppose, too much breathing in other people’s anxieties and emotions. The DNA of strangers.

The man across the aisle, corpulent by even the most liberal of standards, loosens the leather belt from around his trousers, no doubt feeling the acid burn of dinner’s coq au vin. The rest of the passengers shift uncomfortably under blankets or scratch drowsily at itches they can’t quite locate. The atmosphere of somnolence in the cabin is so overpowering that were the pilot to streak naked through the aisles, just for a lark, I doubt very much anyone would notice – much less care. Even Jack and Emmy have passed out, mouths open, as though sprinkled mid-bicker with sleep dust by a kindly British Airways fairy.

God knows, I wish I could sleep on aeroplanes. Disconnected and temporarily excluded from life on earth below, it seems the only sensible thing to do, but as soon as the plane reaches cruising altitude, the moment the signs are switched off and the clink of the drinks trolley soothes the nerves of even the most neurotic of flyers, I fall prey to philosophical musings. While down on earth babies are being born, wars are being fought and couples argue over burnt steak dinners, I sit buckled into my seat and make endless pacts with God. I can spend long hours in this way, plotting personal revolutions, planning get-outs, but always with the safety net of knowing that as soon as the wing begins its downward tilt and the reality of hard ground rises up to meet us, this brave new me, this ghost of my future, will fade back into the ether where it belongs.