I did it while playing Barbies, pressing the plastic faces of my dolls together in a kiss. I had only the vaguest notion of sex beyond making babies and knew even less about my own anatomy. But I had discovered that if I knelt with my heel wedged neatly between my legs, and shimmied around in just the right way, I could summon a feeling so immense it made time stop completely.

The pleasure naturally felt forbidden. Other childhood pleasures, like sweets or TV or jumping in puddles, were governed by adults. This, however, was solely, secretly, mine.

I believed I was the only girl in the whole world who had this power. But later, this changed. It was too much, too good.

It wasn’t a power, I thought, but some sort of sickness. At night, I wondered how to tell my mum so she could take me to the doctor. Thankfully, I never fessed up – but only because I didn’t know how to explain what I was doing.

It was years later that I first overheard a girl at school say the word with repulsion. I scurried home to look it up in the dictionary; masturbation, I learnt, is not something that girls ought to do. I didn’t stop, but for too long I assumed that other girls didn’t feel the way I did.

I gave this experience to the protagonist in my debut novel, Amphibian . It’s a subversive coming-of-age story following two girls as they first discover their bodies and the unexpected transformations that result. While researching it, I spoke with dozens of female friends, strangers – even.