There is a moment in Woody Allen's film Celebrity where the main character's repressed ex-wife, Robin, played by Judy Davis, visits a hooker to take lessons in oral sex. 'What goes through your mind when you're doing it?' asks the hooker. 'The Crucifixion,' replies Robin.

While I haven't quite reached that level, I've always had an acutely active sense of guilt. My earliest complete memory of it is of the time I 'borrowed' Darren Stone's dinosaur book at infant school without asking, hid it in my room for a couple of days until, tormented by my crime, I confessed to my mum, who drove me straight round to his house and made me knock on the door and apologise while she watched from the car. I've never quite shaken off the humiliation of that moment - even though, out of my mum's earshot, I fudged it and claimed that it 'fell into my bag', and had only really nicked the book to get his attention in the first place.

So vivid is that memory, in fact, that I have never knowingly stolen anything since. But as the years passed, the opportunities for guilt seemed to multiply like a hydra. There was sex, of course, and illicit cigarettes and drink, and elaborate half-truths to parents about where you were staying, not to mention all the guilt that teenage girls undergo in the area of food and dieting, as well as a nascent sense of political guilt that prompted occasional bouts of activism and volunteering, which in turn made me feel more guilty that I never quite had the moral fibre to keep them up.

And on into adult life, where greater demands on my time and higher expectations exacerbated a sense of guilt yet further. Here are some of the things I feel permanent low-level guilt about, in no particular order: not being as thin as I have been/could be; not eating properly; not going to the gym more often; wasting money; wasting time; social smoking when I'm supposed to have given up; drinking too much; things I said and did while drinking too much; forgetting to return calls; spending time away from my son - and enjoying it; not being a more attentive daughter/sister/friend/lover; procrastination; tax returns; not doing enough for charity/the environment; saying no to offers of work - not to mention all the things I've put into my body over the years which I knew were harmful (which covers drugs, alcohol and a number of ex-boyfriends).

Does any of this sound familiar? For a long time I'd assumed that this guilt I've always trailed around behind me was the result of an evangelical Christian upbringing, which put heavy emphasis on the notion of original sin and the need for redemption (or, as Flanders from The Simpsons neatly puts it, 'lies make Baby Jesus cry'). But recently, conversations with friends and acquaintances have revealed that seemingly every woman I know, most of whom don't have a religious background, is also weighed down much of the time by unreasonable feelings of guilt. It seems that feeling guilty about our desires - not only sexual, but to do with food, ambition or any kind of personal indulgence - is a peculiarly female condition, even among young, educated women of the generation supposedly liberated from repression and constraint.

Andrea, a 32-year-old management consultant, is single, childless and earns a good salary, yet says she feels guilty about spending too much money on clothes. 'I also feel guilty about forgetting to send birthday cards, cancelling social arrangements, pulling a sickie or doing nothing all day because of a hangover, or if I don't exercise for a couple of weeks - the list goes on and on!' she adds. Kate, 30, a lawyer, also childless, says, 'I feel guilty about most things, though it's usually to do with actions that would impact on other people. So drinking too much is at the top of the list because of the angst the following day - did I offend anyone? Second is not doing enough for friends and family, and not working hard enough.'

And once women become mothers, the guilt seems to increase one hundredfold. Helena, 35, an HR manager and mother of two pre-school children, says, 'I feel guilty for putting my career in front of my kids most of the time - so I feel guilty that I'm stressed and cross with them when I come home and it's not their fault, and guilty at work that my kids get in the way of my career progress. I'm beginning to feel that it's almost impossible to have a successful career and be a good mother.'

Type 'guilt' into an Amazon book search and you will be confronted with almost a thousand titles. Around a quarter of these are crime thrillers, but the remainder are largely self-help books advising us how to live without guilt, and these fall into three obvious categories - food, parenting, sex - all apparently aimed at women. Typical titles include Guilt-free Desserts, More than 135 Recipes to Satisfy your Sweet Tooth without Guilt; Sex Without Guilt (and the more intriguing Guilt Without Sex, which sounds like the worst of all worlds); and my particular favourites, Mommy Guilt and the unambiguously plangent If Only I Were a Better Mother

I'm not trying to suggest that men don't experience guilt, but from the male friends I canvassed, their guilt seems to be much more at a level of personal responsibility or a sense of honour - how they see themselves - than the idea of trying to live up to an invisible standard. Men will admit to feeling guilty about not staying in closer touch with friends or ageing parents, letting friends down in practical ways and missing deadlines or feeling they have underperformed at work, but while most knew they could do more to keep fit or look after their health, only one man admitted to feeling guilty about not putting in more effort to have a better body. Only one said he felt guilty about the amount he drank, and while all but one said they would feel guilty about cheating on a well-established partner, none appeared to have any compunction about being or having been promiscuous when single. None seemed to experience guilt about taking time to do the things they wanted, nor about making their own desires a priority.

So who is imposing all this guilt on women? Is it men, mass media, religion, cultural pressures, other women, society, our own consciences, our impossible expectations of ourselves? Why do we allow these feelings to stunt our ability to enjoy our lives and the freedoms we ought to have? More importantly, how can we teach ourselves to live without it, when most of us already know at an intellectual level how absurd this guilt is?

'I don't think imposing is the right word,' says psychologist Susie Orbach, author of a number of bestselling books on women's self-perception, including the classic Fat is a Feminist Issue. 'I think it's internalised, and we act it out. When I was a girl, the operative word in women's psychology was "shouldn't". You shouldn't have an appetite, shouldn't have desire, you went to school to be interesting to your husband, and we are still unconsciously imparting to our daughters a sense of shouldn'ts. Now we're superficially supposed to have all these things, but the physical space that women are allowed to take up has become tinier and tinier, that can't be an accident. We're not supposed to ever want to eat. And now we're supposed to be allowed to desire, but whether women feel entitled to is by no means clear. I don't think you have young girls binge-drinking because they feel entitled, I think it's because they're bloody confused and don't know how they should manifest their sexuality.'

In part I think the guilt women feel comes from a deeply entrenched sense, tattooed into our psyches from generations past, that we are not supposed to be selfish. Women have traditionally been seen as carers, nurturers, givers, supporters of men and children and elderly parents - the revolutionary idea that we might want to take something for ourselves still sits uneasily for many women, even four decades after the advent of the women's movement. It's a tricky proposition, because for both men and women there is a very fine line between being self-fulfilled and not caring how other people judge us, and simply not caring about other people, and it's only really our individual consciences that can judge where to draw this line in our own lives.

Orbach blames the current levels of guilt among women on the fact that the changes to women's lives originally envisaged by the feminist movement have only come about in limited ways, and on a lack of solidarity between women.

'My generation had to fight to have space in the world and we knew there was an opposition to it, so we had collective forms for trying to engage with our feelings of guilt and inadequacy, whereas the next generation down, whose mums wanted them to have the whole world, didn't have any different psychological equipment than we did, except that you're all supposed to go out there and do it. So you get very humorous books like Allison Pearson's I Don't Know How She Does It, there's the humour of the guilt but it's actually completely tragic, because each woman comes to feel that it's her inadequacy rather than the social conditions under which she's trying to be a mum, or the outrage of consumer culture and the colonising of women's bodies to just be one shape. That's somehow not argued around politically at all.'

So how do we shake off the guilt and sort out our own standards? I set out to find successful women who appeared to be unhampered by needless guilty feelings in the areas of food, sex and motherhood to see what advice they might have for the rest of us.

'I do enjoy eating and drinking and I just don't think it's the worst thing in the world to be slightly overweight,' says Angela Hartnett, Gordon Ramsay protegée and Michelin-starred chef at Menu, at London's Connaught Hotel. 'I think generally you're happier if you're not worried about whether you've got an extra half inch round your waist. Food should be enjoyed, and you can't get away from the fact that if you taste something amazing or smell fresh-baked bread that's just fantastic, you do get real pleasure from it. It's all about eating properly - if you restrict yourself and say "I'm never eating that", you're restricting your natural wants and then the guilt is going to be so much worse because you feel you've let yourself down.'

Most of us already know this in our heads - but how do those of us who have been persuaded by years of diet books and magazine articles that self-denial is good, indulging our appetites is bad, go about changing our thinking?

'I think you shouldn't feel guilty about food,' Hartnett says firmly, 'if you do, that's about other aspects in your life that are making you unhappy and you should find out what that's about, that is where the problem lies. It's easier just to blame it on food and say I'm guilty about food. You have to look at yourself and your personal worth and keep a sense of perspective. I've been on a diet recently because it does you good to detox now and again and cut things out, but that doesn't mean I'll never have a glass of wine again. In the end, my advice would be to like yourself, be happy with yourself, have things in moderation, get an understanding of food. And sit down and have a proper bloody meal, that's the other thing.'

The tyranny of body image is responsible for a vast proportion of the guilt women feel, and often breeds more guilt, because we know intellectually that it's ridiculous to want to be a size eight if that is not our natural shape, yet we still desire it.

'I think it's very sad that a lot of women don't take as much pleasure from sex as they could,' says sex therapist and author Tracey Cox. 'I think that has got a lot to do with guilt, and it's also because they're knackered, we try to do everything and then at the end of the day we have to be this perfect lover, and of course you've got to have the perfect body, and we feel guilty for not living up to that. Women will feel sexy when they're having a thin day - we equate thin with sexy. Men don't even begin to think like that, and neither should they - can you imagine a man thinking, "I don't know if I want to have sex tonight because I've got a bit of a beer gut"? They're the ones who've got it right.'

But the biggest area of sexual guilt that Cox has found in her work is the way we orgasm. 'It's 30 years since the Hite Report,' says Cox, 'and although we've always known that only around 30 per cent of women orgasm through intercourse alone, so many of us still feel guilty if we can't. And our bodies are so complicated that we have to be selfish in bed if we're going to enjoy it, we have to demand what we want, but so many women are afraid of hurting his feelings or not seeing it from his point of view - we're so busy being empathetic!'

Even our orgasms seem to be tied up with body image - Cox quotes a recent US study which found that women with a positive body image reached orgasm 73 per cent of the time, while self-conscious women only achieved it 42 per cent of the time. Compare this to an international survey Orbach recently carried out for the Dove Campaign for Real Beauty, which found that, of 3,500 women between 15 and 64 in 10 different countries across the developed and developing world, only two per cent considered themselves beautiful. That's an awful lot of us not getting the orgasms we could be having. What does Cox advise?

'Ditch the word "normal" for a start,' she says emphatically, 'it's the most annoying word in the whole world. You can have healthy or not healthy, but there's no such thing as normal, stop trying to live up to a standard that doesn't exist. Educate yourself - the more you know about sex the more you can feel in control. And accept that you can intellectually disagree with something but still feel it, so don't beat yourself up for feeling guilty about something even though you know in your head you shouldn't. When you find yourself thinking silly thoughts like, God, my belly, just tell yourself off and don't let yourself think like that.'

Motherhood is more complex. I don't think there's a parent in the world who doesn't feel a degree of guilt that they could have done things better in some way, usually in terms of the time spent with children. But the weight of guilt that working mothers carry is a uniquely modern invention, and we are still wrestling with its implications. Every week a new report seems to emerge telling us that day care is an automatic route to academic failure, Asbos and depression, while stay-at-home mothers, perhaps themselves feeling a little guilty, can slyly pile on the guilt at a more basic level for our failure to contribute to the school-fête cake stall.

'You have to remember that this idea of the middle-class mother staying at home with the children is a recent construct,' says Daisy Goodwin, television presenter and head of her own production company, Silver River, as well as the mother of two daughters aged five and 15. 'It was a post-war idea to keep women in the home when men needed jobs. Before that, working-class women have always worked, and they would have left the children with relatives, while women who could afford it would have had a nanny anyway. So I really don't think we should be made to feel guilty for not living up to something that has never actually been part of women's experience.'

So how can we get past that?

'The only people I will allow to make me feel guilty as a mother are my children,' Goodwin says. 'If I've had to miss something at school because I was working then of course I feel bad, and I do try not to let that happen very often. But I am not going to feel guilty needlessly about the little things, like sewing name tapes in their school uniform. And why should I be made to feel guilty for working bloody hard to give them the life they have? My mother worked and so did her mother, so that's always been part of my experience. I know of women who don't work and still have a nanny. Does that make them a better mother? It might make them a more present mother, but that's not automatically the same thing.'

'I think women are hardwired to feel guilty, but we're our own worst enemies because we've set ourselves such impossible standards,' says Fiona McIntosh, editor-in-chief of Emap women's lifestyle magazines and the mother of two daughters aged six and three. 'Unless you have a successful marriage, a fantastic job, are a hands-on mother and look 10 years younger than you are, you can start feeling like you've failed and that's absolutely ridiculous. I think the first step is to change your mindset and look at what you are achieving rather than what you're not. And step back and set standards that are right for you. I work part-time, and my working friends all say, "You lazy cow", and the full-time mothers I know are amazed I work and say, "Don't you miss the children?" but I know that at the moment I wouldn't want to be full-time either at work or at home. So you have to not pay too much attention to all those other voices.'

Kate Long, best-selling author of The Bad Mother's Handbook and the mother of two boys aged five and eight, brings it back again to the question of perspective. 'If you're smoking over your kids all the time then, yes, that is going to be harmful and you probably should feel guilty. If you're not giving them organic vegetables at every meal, that's not quite the same thing. And the whole debate about going back to work - one woman said to me, "Well, you'll never get those years back". Someone else said, "If you really wanted to stay at home, you could". I couldn't believe it! I think women could be a lot more supportive to one another in that regard. We're not very sisterly sometimes. In the end you have to sort out your own priorities, and if you're showing your child that you love them and you're on their side, those are the things that matter and that offsets a lot of my guilt.'

The answer, it seems, is in keeping a realistic perspective - as if we didn't know that already, but it's easier said than done. Perhaps the first step would be to identify where our guilt is coming from and assess whether there are real grounds for it; if so, what steps could we take to change things?

'Don't be afraid to question the assumptions that are being made around you,' says Orbach. 'Just the knowledge that we are conflicted about our desires can help because guilt can become a default position. Dare to risk being uncomfortable and follow your desires - that's going to be a lot more productive than just being in the guilt.'

Amen to that. As it were.