It was a glorious day, a cloudless blue winter sky. I’ve always loved cold light and I have never seen a bluer, purer sky than when I was on a business trip to Moscow. For me, the Russian capital is the queen of winter skies. Paris, that morning, had a Muscovite feel and lay winking in the sun. Once out of our apartment, in the tenth arrondissement, Louis and I made our way along the Saint-Martin canal towards the Gare de l’Est, weaving in and out of families out for a stroll and tourists mesmerized by the sight of a barge going through the Pont Eugène-Varlin lock. I watched Louis race ahead on his skateboard and felt a surge of pride at the little man he was becoming. I should have told him – that sort of thought is meant to be spoken aloud, otherwise it’s useless – but I didn’t. Louis had changed a lot, in recent months. A growth spurt typical of his age had seen him morph from a puny little boy into a sturdy adolescent, with facial hair starting to show on his still-chubby cheeks, but no spots yet. A fine-looking young man in the making.

Life was all going too fast. I pictured myself for a moment, ambling down Quai de Valmy, my right hand steering a petrol-blue buggy, my left clutching my mobile phone. I do believe that image made me smile a fraction. Or did I dream it up, in hindsight? My memory plays tricks on me; it’s so hard to remember my thoughts during those all-important seconds. If only I could turn the clock back a few minutes, I’d be more attentive. If only I could turn it back a few months, a few years, I’d change so many things.