There are a couple of high-damage periods in the shopping cycle, which we are all familiar with. The six weeks after you have started dating someone who makes you feel like Scarlett Johansson, which requires the purchasing of a new “Look at me, I’m hot” wardrobe. The accidental weight-loss opportunity — suddenly, you need the size-down jeans, in three shades. (It isn’t only Posh). But these momentary lapses are small fry compared with the potentially bankrupting phase that lasts from roughly the second week of June to the middle of July — known as the Pre-Holiday Sweep, or PHS.

During this time, women are shopping slaves. It makes absolutely no difference how much we have in the bank. Nor, indeed, what we already have in our wardrobes. Regardless of the state of our summer-holiday clothes, we abandon all reason and shop — every lunchtime, every tea break, most, if not all, Saturdays — for stuff to take on holiday. This is an endless task. You can, it turns out, never have enough bikinis or sandals. There is always room for another H&M sundress (which you won’t have time to try on, but you’ll get just in case) or a cheesecloth-type thing you could wear over your bikini, or possibly a more expensive kaftan-style thing to wear for lunch, and special outdoor jewellery, featuring shells, that could make the kaftan thing work as evening wear.

Then there are all the stocking-filler extras that are worth a manic trip across town in the rush hour: hair ties with appliqué flowers, straw beach totes with original linings, cotton pashminas. Not to mention the stuff that looks like holiday stuff, but is actually far, far too hot to wear on holiday. But you still get it anyway (that crochet dress from Oasis with the nude slip — I can feel the prickly heat already).

PHS is an annual ritual that stems partly from a fervent belief that your holiday will be life-changing (I resolve only to eat fish and to put leave-in conditioner in my hair — I will be a WAG) and partly from a low hum of nonspecific body anxiety. Also, there’s nothing to do on holiday but change in and out of various inappropriate halterneck tops — and you can’t be sure how much better things will look once you’ve got a tan.

So we reckon that’s a licence to spend six months’ salary, just in case. Holidays are not real life, and we are unrealistic in our expectations of them. We used to think we were going to be Bo Derek. Now it’s Sienna Miller or Jemima Khan.

Given that none of us is going to escape this money-wasting, neurotic attempt at self-reinvention, here are some tips for damage limitation. When you feel the itch, go direct to Office and settle for some Havaiana flip-flops in another colour. You may already have three pairs, but it’s safer and cheaper than a Dolce & Gabbana white towelling playdress. Do not wander absentmindedly into Heidi Klein. You will end up purchasing a £100 watermelon cheesecloth toplet that is expressly designed to prey on those in the grip of PHS. And remember, the urge you are feeling is just one degree off a clinical condition. Breathe...

Times recommends

• Think yourself slim with our hypnodiet podcast
• So, what really makes you happy?
• Paparazzi: A flash in the pan