If you want to do some serious market analysis - find out why your retail operation is on the slide, for example, or why the Conservative Party isn't really convincing anyone with its pale-green makeover - there's no need to spend millions on image consultants or bring in the retail legend George Davies or hire a new spin doctor. All you have to do is go to Nancy Lam's restaurant in Lavender Hill and eavesdrop on a group of Emanuel School mothers having a girls' night out.
They'll have the whole thing sorted out before the Thai green chicken curry arrives, and if you wake up in the morning, as I did, with a bit of a house-white headache, then that's a small price to pay. (You might, like my friend Linda, wake up with a five-Margaritas-and-a-house-white headache, but that's only if you've been to a drinks party beforehand.)
First up for a major mauling: Gap. Time was when we all bought nearly all our clothes from Gap. Chinos and polo shirts for partners, Gap Kids jeans and sweatshirts for the children, and plain black trousers and plain black tops for us working mums. These days, the clothes are designed for the youth market, which rules out anyone of our age because no one over 40 wants to wear a skimpy top that looks trailer-trash cheap but costs £25.
And if we do venture into Gap, we don't want a shop assistant to ask if they can "help with your size" unless they're a plastic surgeon or have demonic powers. Rummaging through the pile the customer has herself just rummaged through is a fruitless exercise unless you can magically transform a size 12 (UK) into a size 12 (US) in the twinkling of a T-shirt. And Gap wonders why its profits are down.
Next up: Big Brother. Why does anyone go to all the bother of switching on the television to see something that is even more tedious than watching paint dry? There's dissension here from Donna, who finds the interaction between the inhabitants fascinating. The rest of us agree that most of the housemates need a good spanking with the business side of a hairbrush, and as for that Nikki and her tantrum about the air conditioning, why didn't she just go and put on a cardigan like any sensible person? Then all those fake breasts - I've seen a balloon artist make more convincing shapes out of inflated plastic.
Third: rap music. We didn't go on marches to support women's liberation in the 1970s just so our daughters could be encouraged to wear next to nothing and lust after some chauvinistic idiot in ill-fitting trousers going on about slapping his bitches. Another job for the business side of a hairbrush.
Fourth: I May Be Over 40 But I am Not a Technophobe. Linda recounts how her twentysomething neighbour recommended a website to her the other day, then asked, with great condescension: "You do have a computer, don't you?" "Five, actually," snapped Linda, the wife of an IT consultant. The rest of us nod sagely at this example of Youth of Today arrogance. I decide this is not the moment to confess that, while watching the England vs Sweden game at a neighbour's house, we had to ask eight-year-old Minna how to turn the volume up.
Fifth: Jo, Tanya, Sandra and Janet warn Linda not to rush into a kitchen extension. Veterans of loft, basement and side-return projects that were supposed to last six weeks and lasted six months, we all shudder in sympathy. "I thought you said you quite enjoyed all living in one room without a kitchen," says Janet to Sandra. "I thought you said it brought you all closer together as a family, back to a more uncomplicated way of life." Sandra looks disbelieving. "Did I say that? I must have been temporarily insane."
At this point, Stewart the Loft Man walks into the restaurant. Stewart is on intimate terms with the underpinnings of many of the women in SW11 and SW18 - the underpinnings of their loft extensions, that is. He certainly knows all about mine. He is Wandsworth's Man of Steel (as in rolled steel joists). "Oooh," whispers Tanya, "he's quite cute." Suddenly, the prospect of building work, turning 50, and life in general, come to that, doesn't seem so bad.