On the radio this morning the Turkish writer Elif Shafak prepares me for a journey. I am listening to Istanbul, she says, and we share the sounds of the city, which dissolve, eventually into water. ‘Everything in Istanbul,’ she says, ‘is fluid.’ And there are two different kinds of fluidity, the elements of oil and water. It is a liquid city, a city that never stops becoming.

Istanbul’s fluidity, its sense of becoming, of becoming another, even at the same time as becoming itself, reminds me of the opening of another work by a contemporary Turkish writer. Orhan Pamuk begins his love poem to his home city: Istanbul: Memories and the City, as follows:

From a very young age, I suspected there was more to my world than I could see: somewhere in the streets of Istanbul, in a house resembling ours, there lived another Orhan so much like me that he could pass for my twin, even my double. I can’t remember where I got this idea or how it came to me. It must have emerged from a web of rumours, misunderstandings, illusions and fears . .  . But the ghost of the other Orhan in another house somewhere in Istanbul never left me.

How many of us must share this notion of a double, breathing our air, thinking our thoughts, eating our food, dreaming our dreams; but also at a remove, always elsewhere, always and inevitably engaged in being someone other than ourselves.