I had no idea that trainers were not the done thing in royal palaces; I knew that it probably wouldn't have looked great arriving in my beaten-up running shoes covered in that morning's mud, but these were box-fresh, as the saying goes, dazzlingly white and the height of fashion (or the height of fashion in Zara, at the very least).
Anyway, there I was, in a grand hall at St James's, enjoying the canapés and the speeches about the work that mental health charity Heads Together was doing, when I noticed, out of the corner of my eye, Princes William and Harry giggling together and looking in my general direction. I thought to myself: "Don't be paranoid, Gordon. They're not laughing at you. THE WORLD DOES NOT REVOLVE AROUND YOU. They're just enjoying some family in-joke."
But after the speeches, Prince Harry came up to me, and guess what? It turned out they were laughing at me, or my shoes, to be precise.
"You know you're not supposed to wear trainers to palaces," Prince Harry laughed, before adding, with a cheeky glint in his eye, that it was ok "because you're wearing your slippers". My slippers and I left feeling 'seen', as the young folk like to say.
It is difficult for men to understand the heavy heart, not to mention throbbing feet, that most women experience as party season approaches. For blokes, Christmas means booze, mince pies and work-approved hangovers. For us, it means teetering along the fine line that exists between a nice night out and an evening in A&E with a broken ankle. Last year, I found myself at the Mind Media Awards, presenting a prize to a student journalist. I tottered onto the stage and narrowly escaped collapsing into the lectern. When, to my surprise, I won an award half an hour later, I decided to go up with no shoes on at all. It may not have looked good, but it certainly looked a lot better than a leg in a plaster cast.
My husband laughs at the trend for athleisurewear – mums who do the school run in sports gear without any actual intention of doing sports. But he doesn't understand how unusual it is for a woman to feel comfortable when out of the house; how very liberating it is to be able to walk as God intended, and not with your hips tilted at an angle that gives you lower back pain, the balls of your feet burning with the weight on them. For a long time, the only acceptable alternative to heels was a pair of ballet flats that would disintegrate in the rain and offered all the support of a flip-flop.
The trend for fashionable trainers, such as the Stella McCartney ones worn by Dame Emma Thompson this week, is a boon for those of us who want to look smart without also risking plantar fasciitis. There are, of course, women who say that they like high heels because it puts them on an even keel with men, height-wise. I get that.
But I also can't get away from the study published earlier this year which found that the reason men find women in heels so attractive is because it makes you arch your back, which signals that you are ready for sex. Heels were, ironically, originally worn by men as a status symbol, but then they were forsaken for their frivolity; after that, it was only acceptable for fluffy, emotional women to wear such an impractical form of fashion.
The times are once more changing. Elizabeth Semmelhack of the Bata Shoe Museum in Toronto believes that once women achieve true equality, then men might start wearing heels again. For the sake of everyone's feet, we must hope not.
