SEVERAL years ago, a doctor prescribed some pills for me that had the interesting, temporary side-effect of making my breasts grow to twice their normal size. As I have always had breasts that were classified as the 'mouthful' or 'handful' type, this unforeseen development did not suddenly present me with 'gigantic hooters', but it did mean that my breasts had, for the first time, become noticeable, and that was quite new for me.

For one thing, I noticed them. Having had a totally integrated relationship with my breasts in the past - I stayed out of their way, they stayed out of mine - suddenly, they began to interfere with everything I was doing. I sat down at my writing desk and they whacked painfully into the edge of it. I tried to stand on my head during yoga and they almost suffocated me. I tried to carry my groceries home in my arms as I'd always done, and I was aware of their discomfort the entire time. Unlike the little ones, they didn't like being mashed against my chest by canned goods. They throbbed in protest.

I wasn't the only one who noticed them. Men were spellbound. The first day that my breasts achieved their full, double growth, I went to the bank and had an experience I had never really believed to be true when other women complained about it. Men were staring at my chest when they spoke to me, instead of my face.

What an odd feeling that is. You have no idea. For someone like me who has never had big breasts, it was totally ludicrous. For someone who's always had big breasts, it must be a lifelong insult. After all, a man is speaking to the part of you he supposedly finds most cogent, but it's not your eyes, the seat of your soul, windows of the brain, but your tits, your mammary glands.

It's also very peculiar. Why would a person speak to glands anyway? Reverse the situation and you'll see how weird it is. Imagine that you held the door open for me and that I turned, stared right at your crotch and thanked your penis. After checking to see if your fly is open, you'd become confused. Does she want me, you'd ask yourself, or what?

And yet, there was some power in it. I definitely felt, for the first time, that a part of my body had mesmerised men and that I could manipulate them. Men's reaction was, in many instances, almost knee-jerk. The bigness of my breasts had a Svengali-like hold over them that I as a person had done nothing to achieve. I realised that if I had been born with a classically sexy body, my life would have been very different. Having a body that brings men to their knees could definitely bring out the dominatrix in a girl, or drive her bats, or both.

Since, generally speaking, a woman is not responsible for having big breasts, being adored for them can bring on the Marilyn Monroe syndrome: feelings of low self-worth. But perhaps, more importantly, it can make a woman feel totally out of control of her own destiny. My friend Elaine was a case in point.

Elaine had enormous breasts. When I first met her, she was 25 and a lovely white-skinned Rubensian creature. Elaine could not leave the house without being harassed. Construction sites were gauntlets to be run. Over the years I knew her, she ceased wearing any garment with a waist and began to gain weight. By the time she was 33, she was very big but much happier. No longer a walking Western fertility object, she could journey outside without being propositioned, insulted, pawed or humiliated. She simply hid away her enormous breasts until, finally, she could live in peace.

Of course, Elaine's was one reaction. There are many 'full-figured gals', as one bra ad calls them, who not only embrace their opulence, but also use it to advantage. All the sex goddesses come to mind, the Jayne Mansfields, the Diana Dors. (Funny, I can't think of any modern actresses who are known primarily for their huge breasts. See how far we've come?) And, of course, there is Dolly Parton, who, I read in the tabloids, has had so many breast implants that she can no longer stand upright. Though I wouldn't bet on it if I were you. And then there's the loving, maternal aspect of big breasts, which Tom Wolfe missed so much in Bonfire of the Vanities when he wrote about the painfully thin, older society women whom he termed 'X-rays'.

I quite liked my own big breasts. I took a photograph of them so I could remember them when they were gone. And while I had them, I felt they were rather like dolls I could dress up and take out for an eventful, though not too athletic, outing. I was interested to see that I was as influenced as the next guy by the idea that bigger breasts were better - not easier, but certainly prettier, more exciting, and generally better. But I can't tell if I was programmed to feel this way, or if I was prejudiced because my large breasts were sudden and new, like a new hairdo.

Of course, it's wonderful when the men you love, or even like, respond enthusiastically to your body. But you know we're not talking about them. We're talking about the numerous men whom one does not know, who feel that because one has big breasts, that's grounds enough for discussion, if not acquaintance, right away. Think of it as if a lot of women came up to you on the Underground and said: 'You've got a large penis, haven't you, buddy] What's up?' Or worse: 'He's got quite a small one, hasn't he, girls? Want a drink?' Over and over again. Believe me, you wouldn't like it. You wouldn't get used to it. And it gets old quick.

It would be interesting to know, if impossible to calculate, the extent to which men's reaction to big breasts comes from persistent reinforcement in advertising, television, films and so on, or whether it is simply genetic. We know that in hunting and gathering societies in which women do not wear breast coverings, men do not walk about with their eyes popping from their sockets and tongues lolling from their mouths. So that's a clue.

On the other hand, as Desmond Morris, the zoologist and writer on human and animal behaviour, will tell you, breasts are a secondary sex characteristic, whose importance was accentuated when humans stood upright, and the bigger the breasts, the bigger the sex characteristic.

My boyfriend, who has worked in the art departments of several men's magazines, maintains that, in this era at least, breasts are the only safe sex characteristic. It is the safety aspect that explains why, when men have been saturated with the sight of more naked breasts than ever (well, at least since Graeco-Roman times), they persist in being obsessed by them.

Despite the fact that I found my temporary big breasts noticeable, women born with big breasts are, of course, as used to them as I am to my small ones. Although breasts may be sexually sensitive, women usually only pay close attention to them when they use them to feed babies, or when they need medical attention.

Breasts are not, as penises seem to be to men, fleshy pals to a girl, worthy of names or companions in conversations about sexual conquest. Women do not speak to their breasts in novels or films. Breasts are, well, just there. Which is why it's doubly odd when some man in a bank queue is leaning over and speaking to them.

It's not that we mind, really. It's just that the obsessive nature of men's interest in breasts can make a man seem not only foolish, but also shallow. And, strangely, not very interested in women. Men's obsession with breasts is something men share with other men, like sports. Explaining it to a woman, even though she knows that's how it is, is like telling her the reasons you love her gall bladder.

But women do want men to like them sexually. That is universal. And since we know that men love big breasts, this has led a lot of women to get breast implants. On the surface, they could change a woman's sex life for ever. And yet, even here, women can't win. For in addition to getting odd diseases of the immune system from the plastic, women say that, although men love the way the implants look, they hate their hard and lumpy feel, indicating that there is more to this breast business than meets the eye.

Men's disappointment in the feel of breast implants is interesting. It indicates that it is not just the shape or size that arouses men, but also the anticipation of its feel, of squeezing it or lying on it. So it does have something to do with the woman to whom it's attached.

Also, as much as men make jokes about sagging breasts, it seems that the interaction of gravity and breasts, the realness of this condition, has something to do with what makes them human and exciting to a man. It's what makes them squeezable and good pillows.

When I stopped taking the pills, my big breasts went away, and I was back to being a woman men like for her face. That's fine with me, but it is very different. Men don't feast on your face in the same way. It's more of a worship. Quieter. More reverent. There's a certain Rabelaisian flavour that enters your life when you have a great body that I had only glimpsed, and it both repulsed and attracted me.

It attracted me, I must say, not because it directly made me feel more sexual, but because it made men feel more sexual and that gave me power, which made me feel more sexual. If a woman was born with a great body and a great mind, I wonder which she would develop more? A pity that Truffaut is dead - he might have made a film about it.

Emily Prager is the author of 'Eve's Tattoo' (Chatto & Windus, pounds 8.99). (Photograph omitted)