A few things marked me out as different at school. My sandwiches, for one, didn't look like anyone else's, save for my Polish friend Alex's - hers were similar. My lunch was made out of big, thick slices of bread, often with one side white and one side brown; they very often encased last night's dinner, meat loaf and pickled veg being one of my favourites. I never had crisps, just fresh fruit, and often fennel for its digestive properties. (Lord, if I had a pound for every time I was asked if I was eating an onion!)

Of course I hankered - with hindsight, how stupid was I? - after the floppy, sliced-white-bread ham sandwiches with crisps that everyone else had. Years later, I discovered everyone had eyed my sandwiches with rightful envy. But what else made me stand out was that, in the winter, I wore turquoise Damart vests. They were so bright that, as I undressed in the changing room, my classmates would cower and have to shield their eyes. No one else had them, as we got ours from our Parisian uncle who had long praised their qualities (Damart had launched in the UK, but very few people seemed to know about it).

Naturally, I ditched the vests as soon as I left home and school. Some years later I became fishing correspondent of a national newspaper and the job involved fly-fishing week in, week out. This was fine when it was summer and I was being treated to a picnic on the Test, but salmon fishing on the Tay in January, or grayling fishing in thick snow in February, was another matter. Thermal underwear was once again called for and my search began.

Marks & Spencer was my obvious port of call. I stocked up on long-sleeved vests and long johns in boring black or white. No turquoise in sight, thank goodness. I wore them in good faith, but they were no warmer than just another layer of clothing. I was not as toasty as I had been all those winter mornings on the netball pitch, being screamed at by the spaniel-keen games mistress. Then I spent far too much on thermal underwear from the "performance label" Patagonia. Better, but I still did not resemble the people on the Ready Brek adverts.

I went to see my mother and asked her for the Damart catalogue that I had, for so many years, scoffed at, with its pictures of foot-muffs and lightning flashes denoting how warm each item was ("that which you mock, you will one day seek out"). I looked for the familiar, comforting and unpronounceable word - "Thermolactyl" - that meant one thing only: true Damart thermals. There were now really pretty vests with spaghetti straps, in all sorts of colours; the black ones looked positively sexy. I bought lots and proper warmth was mine again.

As I write this (it is zero degrees) I am wearing a long-sleeved, pointelle Damart thermal vest. It could have been pink or violet or any number of field-flowers colours. But, for old time's sake, it is gloriously turquoise.