It wasn't a particularly good day to go sight-seeing. We had already missed our chance to go up the Eiffel Tower; you might as well forget about it if you aren't queuing up with all the Chinese tour groups by 9.15 in the morning. For some reason that was hard to explain to my four-year-old son, Rafe, the children's playgrounds were all closed.
If I had been on my own in Paris on this cold, windy morning, I would have dodged into some little bar, settled in for an hour or so with a newspaper, and ordered something dark and fierce. (If you are alone in a French bar in the morning, by the way, remember not to ask for white wine. That is taken as an incontrovertible sign that you are an alcoholic. Order as many brandies or Ricards as you like, and there is never a problem about a few glasses of red. If you ask for a white wine, though, people look at each other.)
But I wasn't alone. Rafe's mother was in her native South Africa, doing the rounds of her family, and I was his sole companion and entertainment manager. We were going stir-crazy in our flat near the Champs de Mars: elements from the Monopoly set were spread everywhere, and there were plastic knights, balsawood planes and space guns on every surface.
Since it was a public holiday, a lot of things were shut. But dear old Rafe is game for anything, especially if you can present it to him in the form of a search or a quest. 'There's a writer I like who lived in a flat quite near here,' I said. 'We could always go and hunt for it.' He went quiet; not a good sign. 'Actually he died there.' That did it. There is something about death that attracts and scares children in equal measure.
'It was ages ago — nearly 90 years.' Rafe, having no clear sense of time, wasn't put off by that. Nor was he interested in who the writer was; until I dug out a book and showed him an etching made on the writer's deathbed, his luxuriant black beard pointing slightly upwards.
'His name was Marcel Proust, and he wrote a very long book about all the people he knew. Some of them were quite angry when they read things about themselves.' The etching did it: he agreed to come on a Proustian expedition to the rue Hamelin.
To be honest, I still haven't managed to finish A la Recherche du Temps Perdu, even in English, and in French I've scarcely got halfway through the famous first volume, Du côté de chez Swann. But then I like Shakespeare, and I've only seen half his plays. Proust's writing appeals to me, that's all: his sly humour, his wonderful, complex, lush descriptions, his understanding of the human heart.
Twenty years ago, as I was passing the building near the Opéra where he had lived as a child, I noticed that the big courtyard door was open, and dodged inside. Upstairs was an office where the Prousts' flat had been. A bosomy lady in her 50s was sitting at a desk with a phone on it. Could she help? Well, I stammered, I'm really just looking... I thought I'd see where...
'Who is it?' called another woman irritably from the next room. 'Ce n'est qu'un Proustien anglais,' said the first one in a comfortable, tolerant voice: it's only an English Proustian. Now she was giving me a motherly smile.
I swelled with pride, as I dodged too quickly through the office looking around the rooms, nodding to everyone and thanking them. An English Proustian: it was like being awarded the Ordre des Arts et des Lettres. For ever afterwards I've had a kind of proprietorial feeling for Proust. Monsieur Proust, by Céleste Albaret, who looked after him for the last eight years of his life, is a favourite book of mine. She was in her early 20s when she went to work for him in 1913 until his death in 1922, and she lived on until April 1984, dying at the age of 92. I could have gone to visit her myself, if I'd only had the sense.
For decades after Proust's death she refused to talk about him. Then a journalist called Georges Belmont went to see her, and she agreed to give him the entire story. It was published in 1973, and a superb film, Céleste, was made of it just before her death by the German director Percy Adlon.
It is obvious that she thought of little else but Proust during the long years, and her memories were quite remarkable. At first my suspicious journalist's mind thought she must have made a lot of it up, but it became clear there were lots of things she could have 'remembered' with advantage, but admitted not knowing.
So Rafe and I headed off to find the fifth-floor flat at 55 rue Hamelin where Proust and his Céleste passed their final time together, in the bedroom/writing room whose cork panelling had been transferred from his more famous flat at 102 Boulevard Haussmann. We battled against the wind and rain, as I peered inadequately at the small map and got lost more than once. For a four-year-old, Rafe is remarkably forgiving.
But this is not a story with a satisfactory ending, unlike Proust's Le Temps Retrouvé (Finding Time Again), which ends his masterpiece. (Actually, having never got that far, I don't quite know how it ends, but according to Céleste, Proust was delighted with it when he finally put his pen
down; only to start the endless rewriting process immediately.)
Sadly, rue Hamelin is an unattractive little street, and we couldn't find a no 55: presumably the houses have been renumbered. I'll have to do a bit more research. And next time I'm not sure I'll be able to con poor old Rafe into coming with me.
John Simpson is the BBC's world affairs editor and can be seen around the globe on BBC World News, available in 200 countries and territories worldwide, and on selected British Airways flights.