Iwas barely five years old in 1973, when the novelist Nancy Friday’s cult classic, My Secret Garden: Women’s Sexual Fantasies, began making its way on to the bookshelves and into the handbags of millions of women. What Friday’s book revealed was that – unconstrained by assumed social conventions, self-consciousness, or perhaps the fear of making our partner uncomfortable – in our imagination we can indulge in our deepest, most transgressive desires. It was provocative, even revolutionary, at the start, and then it became required reading, a global bestseller. I read My Secret Garden for the first time when I was preparing for my role as the sex therapist Dr Jean Milburn in the TV series Sex Education. I am a woman, with a sex life and fantasies of my own, and I was curious to know how women’s deepest desires had changed in the 50 years since the book was published. In which ways would a diverse group of other women’s fantasies be similar to, or different from, mine? I sent an invitation to women across the globe to share the sexual fantasies, thoughts and feelings that so many of us hold in our heads but so rarely speak out loud. A chance to gather a new book of fantasies for a new generation. For me, sex has never felt like a static entity, but rather something that adapts and changes as I grow and change, with every new phase and stage of my life. A huge part of this has always been in the thinking and the feeling, not just the doing. As an actor, there is an inherent permission at the core of my job to give myself over to an alternate reality, which is the very definition of fantasy. The women whom I embody, whose worlds I step into, also have inner lives, desires and fantasies, which are vital to understanding what makes them tick. And a fair few of them have taught me about sex and sexuality. If I’m honest, I think there are two sides to me, as perhaps there are to many women: the side that is good at asking for what I want and the side that will concede to my partner’s desires, that is happy to share my innermost urges but only if my partner starts the conversation (and then not all of them). Is that due to shame? Or an indication that I wouldn’t trust anyone with that level of intimacy? Or is it that I think it’s somehow better to be, in part, unknowable? Do we all, in some way, struggle with being totally knowable? If I have one hope for the book, it is that it will start a new conversation about sexual power, particularly for women. Sexual liberation must mean freedom to enjoy sex on our terms, to say what we want, not what we are pressured or believe we are expected to want. One thing is for sure: sexual fantasy continues to play a vital and healthy role in our lives as women and genderqueer people. And all of us have the power to say – and get – what we really, really WANT. Romanian/in a relationship/bisexual One of my most meaningful sexual fantasies was born out of a frustration created by a religious dogma: in the Orthodox religion, women are not allowed to enter the altar. My separation from religion occurred around the same time that this fantasy was born. Before I die, I must find an empty church – be it abandoned or not – and I want a man to go down on me as I lie on the altar and my moans of pleasure to fill the echoing room. I even fantasise that I find a young priest who is willing to do this and is not afraid that his God might punish him, as I believe sex can be one of the most religious experiences of our lives. Scottish/married/pansexual I have been with my husband for 13 years, married for 12. After we got married, our sex life was pretty nonexistent – not due to lack of attraction, but instead due to his severe depression, self-loathing and the impact of an overbearing mother. It left me feeling empty and lonely. In order to cope and to feel a sense of affection and love, and to reach orgasm on my own, I began to build a fantasy world. Sometimes I’m a survivor in a zombie apocalypse or a witch in a wizarding world. I can build on these fantasies for months, and then start a whole new one. In reality, my husband and I have sex maybe once a month now. We have a respectful, kind and fun relationship. Part of me wants to retreat into my fantasy world but, for him, I try to stay present in our lovemaking. Still, the level of rejection I felt for many years was incredibly destructive, and I know without my fantasies and my fluidity in imaginary world building, I probably would have ended my life. Undisclosed location/single/ heterosexual For a long time now, my fantasy has been about a dominant man. An affluent man with a great job who’s really, really good in bed. The “Christian Grey” fantasy. Every single boyfriend I’ve ever had, since I was 17, has been shit at sex and needed looking after in some way. They were usually skint and lacking real sexual experience. In my fantasy, I’m with a man who surprises me with restaurant reservations without checking with me first. He buys me a new dress and leaves it out on the bed with a note that says “Wear this”. I’m picked up in an expensive car, he pays for the meal, of course, and then in the bedroom I don’t have to do a thing. I’m completely submissive and pleasured beyond belief. New Zealander/married/pansexual I have two main sexual fantasies. In the first, I’m not me, I’m younger, thinner, and I’ve met Harry Styles and he really likes me and wants to spend time with me. I’m usually a writer or a lawyer, very successful in my own right, and after a few dates and time spent together he starts telling me how much he likes me and wants to be with me and only me. Then it moves into very hot, sensual, passionate sex. The second fantasy always involves my partner and another woman wanting to have sex with him. When I think about it out of the context of the fantasy, I feel it’s a bit perverted and I’m uncomfortable with just how desperate she is to be fucked by him. I quite often cry after I have this type of fantasy. I didn’t fantasise during sex with my partner until quite recently. He had an emotional affair with a woman, and when we were having lots of desperate sex, I fantasised a couple of times that he was fucking her. I cried after I did that also. Australian/in a relationship/bisexual I am a machine. I am moving rhythmically to a beat and pumping. But I am also a machine that is pumping out nutrients. I am being consumed. My lover is suckling at my teat. Another is sucking between my legs and drinking the juice. Feeding. My eyes are rolled back, we are all mindless. I’m being devoured. I am meat. I am milk. I am fruit. I’m keeping them alive. I am nothing except for this purpose. Like a sow with 20 piglets hanging off her teats. Their hunger has become their pleasure. They are now strong. I’m being pumped back up after giving my fluids. Then our juices overflow. We are full. We stop pumping. We are oiled up. We slide apart. My lover and the others get up and move on. The next lover arrives. They attach to my teat and start to suck. They start to eat. I start to feed them. I am keeping them alive. I am being devoured. I am a machine. Chinese/single/heterosexual My deep-seated fantasy is for a man to be indelibly – and entirely ordinarily – nice to me. I do not long for flowers and speeches and thoughtful presents, nor a vacation at great expense. In my fantasy, I am not spoiled. The thought to which I grow wettest is of a partner who takes care of me in bed, who aims to make our bodies and their pleasure mutually familiar, who is accomplishing all of that niceness in the most generic sense of that term. Mestiza Ecuadorian/single/bisexual I would like to have a penis. That is my fantasy. I love my boobs and my femininity. But I would like to have a penis to fuck a woman, or many women, with care and protection, but also with fiery desire and to feel the pleasure that men feel when having sex with a woman. Isn’t that funny? British/married/bisexual My absolute favourite fantasy is unfortunately never ever going to happen as it involves a room that I access through my full-length mirror where I am waiting for myself. No, I am not a narcissist (although a narcissist may well say that) – I just love the idea of being totally free to experiment with someone who knows me as well as I know myself, needing no mood-interfering guidance and to feel that total lack of self-consciousness. This is an edited extract from Want: Sexual Fantasies By Anonymous, Collected By Gillian Anderson, published in the UK by Bloomsbury on 5 September, priced at £18.99, and in the US by Abrams Press on 18 September, priced at $28. To support the Guardian and Observer, order your copy from guardianbookshop.com. Delivery charges may apply.