Lucy Porter: My inner Lady Gaga emerges at the sales

Exciting findings this week from one of those surveys conducted on behalf of a company you've never heard of and will never hear of again (Shape Smart – see?) This one claims that in January the average woman wastes £71 on "sales bargains" (a glaringly obvious oxymoron that I'd never noticed before) that she never wears because they're the wrong size.

I like to think I'm a pretty average woman – at least I would be if it weren't for the tusk – and I don't dispute the fact that in the sales I buy clothes that don't fit. I've never really thought of my sales purchasing as a waste, it's simply a yearly ritual. At Christmas, I leave mince pies and sherry out for a fictional, fat, bearded man. In the sales, I buy clothes for a fictional slender, perfectly proportioned woman who has completely different tastes in clothes to me.

I gave birth nearly four months ago, and I put on about a stone-and-a-half during pregnancy. Since then, through a careful programme of healthy eating and gentle exercise, I've managed to put on about another two stone. So naturally, I have just popped into Topshop and bought a sequinned skating skirt in a size six. Even pre-pregnancy I had chunky legs – now a skating skirt would look like someone has popped a pelmet on the Petronas Towers.

The skirt is also the perfect, impractical sales purchase because I hate skating and never have occasion to wear sequins because I'm neither six years old nor a drag act. Like most people, I wear the same outfit 99 per cent of the time – jeans and black things – but that doesn't stop me from snapping up some velvet plus fours and a tricorn hat in the sales. My husband is utterly sensible, and only ever buys jeans and T-shirts that he will actually wear (maybe it's a man thing). Then again, he is not the typical man because he's 6ft 5in tall and has to get all his clothes from a special shop at the top of a beanstalk.

The most shocking thing about this survey by Shapeshifters, or whatever they were called, is the amount of money women are claiming to spend. Either my inner Lady Gaga is much more expensive to keep than average, or the women in this survey have been lying. If they're only squandering £71, then I'll eat my hat. It's a feathery one I bought in the sales and it really doesn't suit me.