Boys grow up by getting bigger, stronger, louder. The things that a male child is encouraged to be good at are, by and large, things esteemed in the male adolescent too. But for girls, adolescence is a time of loss. Becoming a woman means giving things up, explains Deborah Cameron in The Myth of Mars and Venus, and taking up new and feminine occupations: “In particular, [girls] abandon physical play: instead of using their bodies to do things, they start to focus on adorning them.” Somewhere in the passage between being a child and becoming a grown-up, girls learn that our bodies are not ourselves, but a portable property that we must cultivate, display, and trade for the best bargain we can make.

I stopped climbing trees. I learned to shave my legs. The grazes on my knees faded. The scabs on my shins bloomed where my clumsy razor peeled away ribbons of skin. I was embarrassed to sweat. There were no lunchtime games of netball for girls at my school – just the option to walk circuits of the field, talking, looking, always wary of a rogue shot from the boys’ football game. I decided I was not a physical person. It would be undignified to run – and so began a long career of dodging PE, which got even easier once I was at secondary school and could claim period pains. I was not a physical person, I was just rendered physically incapable of taking part by my female physiology.

I was lying when I dolefully clutched my belly and pleaded cramps, but it was true that my body was the thing stopping me: my flesh so pale and so horribly fleshy, striated with stretch marks and all the bits the wrong shapes. It felt unthinkable that I would have to go through life represented by this grotesque object. I stopped idolising the capable, outdoorsy girls of Arthur Ransome’s novels. One day I heard a reading of a short story by Janet Frame, about a young man “so bedevilled by the demands of his body that he decided to rid himself of it completely”. I listened, rapt. It seemed such an attractive solution (the story is called “Solutions”) to the problem I had with myself, and such a shame that it did not work out better for the young man: in the end, some mice mistake his disembodied brain for a prune, and eat him, or what’s left of him.

The insistence that women are no more than our bodies has historically been a means to limit us, tying us to the supposed power of our hormones like dogs chained to stakes, extending the symbolic nothingness imposed on the holes and hollows of our bodies to void our claims to humanity. A clever girl can answer that by declaring “I am not my body”, but it is a bad answer. Only women are asked to choose between being our bodies and being a person. The male body is uncontroversially a human body, conferring human status. A female one is a liability, a disgrace. Safer not to see yourself within it, but to set yourself apart, and imagine your body as a thing to be improved and exploited.

There are several fields open to the woman who accepts the escapologist’s vision of her body as object. Prostitution, for example: a frequent defense of prostitution is that the women within it “don’t sell themselves, they sell a service”, as if that service didn’t involve the most intimate access to the body, as if our bodies were not ourselves. Or commercial surrogacy, where a fertile womb is simply a warehouse that can be leased over and over. These things are perfectly consistent with a society that treats the female body as a thing, and so too is the dull grind of obligation sex, where women dutifully make their bodies available for their partners’ satisfaction, with no expectation of their own pleasure.

It’s only possible to believe all those things are harmless if you believe there’s no one at home in the female body to be harmed. It’s a useful fiction for those who find women’s humanity an inconvenience, but it is a fiction. The young man of Janet Frame’s story, finally rid of his hateful body, “could never any more proclaim his identity… nor could he see that he was lying in a dustbin; nor could he feel anything except a roaring, like the sound in an empty shell which houses only the memory of the tide”. You cannot escape your body; there is no you without it. Our being resides in our limbs, our skin and all our senses.

Which is why I cried at Caitlin Moran’s letter to troubled teenage girls. “Pretend you are your own baby,” she says. “ Your body wants to live – that’s all and everything it was born to do. Let it do that, in the safety you provide it. Protect it.” I wished that I had thought of those words at 12, at 16, at 22, at all the times I’d made my body my adversary. But I wished also that I and every other girl had never been pushed through that brutal border crossing which makes you an alien in your own skin. I wish that girls would never have to pretend they are their own baby, because they were never forced into exile from themselves. You are your body, and your body – tender, needy, sticky and vulnerable – is a beautiful and human thing.