There once was an ancient Greek general by the name of Theseus, who went on a long and arduous sea voyage aboard a magnificent ship. The journey lasted many years, and with each trial the ship and its crew faced, a different part of the ship had to be replaced: the hull, the mast, the oars, the helm.

At the end of its voyage, the ship had been through so many ordeals that every single plank that had once made up the ship had been replaced.

Can we consider this to be the same ship that first embarked on its voyage? And if not, at what point did the Ship of Theseus cease to be itself, and become a different ship entirely?

The question of the Ship of Theseus doesn’t have a straightforward answer, but it is a question that’s worth pondering. Consider this: Seven years from now, every cell that now exists in your body will have died and been replaced by a new cell.

Are you still the same person? And if not, at what point did you change?

When I was younger, I tried to answer the question myself, and believed that I had come to a valid conclusion: The Ship of Theseus was still the same ship. It was not the material that made up the ship that mattered, but rather the crew that was on board.

In the same way that a ship is not merely the sum of it material parts, we cannot be reduced to mere carbon atoms. We are composed of stories, and emotions, and memories.

It is an idealistic notion; memory – like innocence – is easily lost.

A city is more than just collections of brick and mortar: it is a nexus of collective memory, a repository of a million stories. Each story follows its own trajectory, but they all share the same underlying theme.  I am here. I exist.

Our perceptions of the world are chained to the tyranny of the everyday, to the notion that things will stay as they are. But the neon lights of Hong Kong – the backdrops of Blade Runner and Chun King Express – will soon become figments of our collective memories. Venice is sinking beneath the waves.

In The Metamorphoses, the Roman poet Ovid wrote: Omnia mutantur, nihil interit. ‘Everything changes, but nothing is truly lost’. But what is left of Augustus Caesar’s Rome, which he found in clay, and left in marble? What stories will we find beneath the shade of indistinguishable skyscrapers?

The sand in your neighbourhood playground is replaced with rubber; the old man who once sold you coffee disappears; an apartment block is torn down. The street you’re standing on is no longer the same.

Editor’s note: Our latest series, Train Stories, aims to provoke questions rather than provide answers. We accept think pieces, flash fiction and musings on urban culture. Our only criteria? The piece has to be short enough to be read in the time it takes for a train to travel from one station to the next.

To submit your story, contact us at submissions@departuremag.com.