Thirty years ago, the average man thought the clitoris was a Greek hotel and the average woman didn't know how to enlighten him. A man's sex education consisted of what his misinformed friends told him. As an editor on British national newspapers, I received letters from confused and timid women, which made it clear that sex, from a woman's point of view, needed to be explicitly addressed.
During this period, despite the Swinging Sixties, the perception of sex was that everybody did it. You could sunbathe topless, wear see-through dresses and fornicate more than previously, but nobody actually talked about sex: it was considered embarrassing.
The contraceptive pill had recently appeared but few women felt sexually self-confident. Women, and young girls especially, were being pressured by their boyfriends to have sex. Girls were hesitant, confused about sex. Not that they didn't risk pregnancy... should they or shouldn't they? Did first-time sex leave you feeling like a goddess or a doormat? Would he still love you tomorrow? What did 'being good in bed' actually mean?
The only sex education I received from my mother was by way of a book that featured goldfish - had I fallen in love with a goldfish I would have known exactly what to do. My friends were given similar birds-and-bees publications. We actually learned about sex from a banned blockbuster, Forever Amber by Kathleen Winsor, which was passed around school in a dust jacket of A. A. Milne's When We Were Very Young.
Mindful of this, I finally wrote my textbook as a novel, and Lace was subsequently described as the book that taught men about women and women about themselves. Lace gave the reader explicit information about sex. It helped women to discover their sexuality and take charge of it: it generated the murmur of bedroom guidance, 'Up a bit... down a bit... more to the left... MY left'. Teenage girls passed Lace around in secret, so in a roundabout way, I reached my target audience.
Somewhat surprisingly, I encountered no negative reaction to Lace, except in Kansas City. On my American publicity tour I flew into that town around midnight, only to be told that the City Fathers had forbidden me to make any appearances in public on radio or TV, because I was making my living from sex. I was 50 years old at the time, a bit late for entry into the sex profession, but delighted to have a day off in the hotel, and wash my backlog of underwear, as a good sex worker should.
Today, girls may know more about sex but Lace's message of empowerment and equality is as relevant and important as it was 30 years ago. It's a pity that modern novels, especially informative ones that involve women's sexuality are put down as 'mummy porn', 'bonkbusters', 'bodice rippers', 'beach-reads', 'wank-fodder' or, simply, trash. But what has clearly been proved, and what has changed in the last 30 years, is that women are far more openly interested in having an enjoyable sex life.
These days the perception of sex is everywhere - you can't get away from it. The other day I pressed the wrong button on my TV remote and there before me was a glistening 18-inch lavender penis, waving gently. Male magazines are in full view at the local corner shop, and where modern children learn about sex is on the internet. What's that you mutter? The parental control button? Don't make me laugh.
Unfortunately, 'sex-as-business' productions are male-filtered, and so reinforce male misapprehensions about female sexual needs. They can also persuade some women that they must be abnormally unresponsive when they are not.
Another result of sex-as-business is that teenage boys expect a naked teenage girl to look like the plastic-enhanced ladies featured in the media, with melon-sized boobs propping up their chin, legs lengthened by six inches courtesy of photoshop, and bald genitalia.
Teenage girls have always felt not-good-enough, but now, as a result of male comparison and criticism, they borrow dad's razor, buy their own Ladyshave or save up for a full Brazilian; they plan to have breast implants and facial silicone injections as soon as they can get their hands on enough cash. Sometimes feeling not-good-enough leads to bulimia, anorexia or a victim mentality, and it always leads to lack of self-confidence.
What has changed since the Eighties is that now women talk frankly about sex over coffee in a work break, in the kitchen at home, or when choosing lingerie at an Ann Summers gathering (the modern equivalent of a Tupperware party).
What is not yet discussed by either sex is female masturbation, which remains a taboo subject. Men think it is a) filthy, b) an affront to masculinity and to themselves personally. Nice women don't do it.
But we do.
On the other hand, male masturbation is a) only natural, b) provides a healthy relief before marriage or when a woman is not available, such as in prisons, warships, tents and tanks or anywhere, anytime, when alone and unobserved.
After the nine o'clock TV curfew, when all 14-year-olds are safely tucked up in their bed, TV comedians hurl male masturbation jokes at audiences, which roar with the laughter of recognition.
The French writer Colette once wrote that a good lover is one that can do it better than you can. Maybe that's why men don't like the idea of a woman being able to please herself. This is one perception that hasn't changed a bit in 30 years - both in bed and out of it.
Follow Shirley Conran on Twitter: www.twitter.com/shirleyconran