The sketch caught my eye as we walked under a bridge of the Seine, during the last January of the 20th Century. I did not mention it until we were well beyond the shabby little stall in which it stood, for sale.

‘You know, Martin, I really liked that charcoal drawing.’

There was something in the face of the young man which spoke to me. He was, without doubt, French; an inference I drew  from his saucer eyes, his double-thick eyebrows, and the indolent, baggy-shirt pose he adopted as he sat backwards on a chair, eluding the artist’s gaze.

Martin pulled at my elbow, and we turned into the biting wind, back to the makeshift market.

Just this weekend, old friends visited me in Dublin for the first time. One of them complimented the art on my walls, looking at the French charcoal drawing as he spoke.

This is the sketch, I related, somewhat extravagantly, that changed my relationship to art.

The day I bought it, for 200 francs, was the day I understood that art is not about following what other people think, but acting on what you think yourself. And although prints of famous stuff are nice, original art, no matter how humble, is nicest of all.

It was a lesson Martin taught me.

If you really like something, he had said, don’t let it go.

I protested, describing the hassle of bringing the framed picture back to London, where I lived at the time.

But I indeed bought the sketch of the charcoal young man, and he has followed me these 23 years.

A couple of times, across more than two decades, I have glanced at the artist’s signature, dated ‘94, in a half-hearted and futile attempt to trace who it might be. The name ‘Sole Malherbe’ didn’t make much sense, and a Google search brought me nowhere.

I dated a young man in Strasbourg in 1990. He, like me, was 24 years old, and had just been released from military service. He offered me a cigarette. I did not smoke, but accepted. Smoking gave us something to share. It broke the silence.

We left the unnamed bar in which we met that first night, and he walked in front of me, out onto the street. His stride seemed exaggerated, and vaguely askew. As if his civilian shoes were too light for his feet.

The affair was brief, and driven by him. He knew what he wanted. I had access only to my fears.

I can see his features now, looking at me in disbelief as I closed it all down; and him looking away as I arrived to the final part, suggesting we could be friends.

Sometimes, I find the memory of his face in this sketch on my wall. Although Time can conflate our recollections, contriving to bend them towards a single, touchable thread.

With my friends safely in a taxi back to their Dublin city hotel, I stood pondering the sketch again, in that absent-minded calm that descends when the guests have departed and the night is done.

Studying the artist’s signature on the bottom right, I did a double-take. For the first time, I saw a different name in the assembled letters. That’s not ‘Sole Malherbe’, that’s ‘S. de Malherbe’.

Wine in hand, I returned to Google.

When she replied to my email and photo wondering if she was indeed the artist, Stéphanie de Malherbe was both excited and enquiring.

Haha! Yes! That’s my drawing, she said. From my very first exhibition in the Rue Vaneau in Paris, in 1994.

The mystery, from her point of view, was where I came to acquire it in 1999, and who had sold it to me.

I explained that I had picked it up in a bric-a-brac stall, under a Parisian bridge. I did not mention it had cost me twenty quid. This detail seemed unkind, given the skill and love that I could perceive within her charcoal strokes.

Stéphanie is now an established professional artist, with a formidable resumé and thriving exhibition schedule.

My sketch had come from the start of her career – we are of a similar age – when she supplemented her income after graduating with privately commissioned portraits.

Thanks for your surprise message, she wrote, which has so evoked my younger life.

We agreed to stay in touch.

It is a satisfying journey, to connect with an artist who has anonymously given such joy.

But each solved mystery begets another.

Who commissioned the charcoal portrait in my possession? Why did he part with it? And, where is he now?