Born in 1979, Irene Vallejo is a Spanish writer, historian and philologist, and a regular columnist in the newspaper El País. She had written several books, including novels, essays and children’s books before she published El infinito en un junco (Infinity in a Reed), which won a number of prizes in Spain including the National Essay prize and spent 18 months in the bestsellers’ list there. Mario Vargas Llosa has described the book as “a masterpiece” and it has now been published in 30 countries. The English translation by Charlotte Whittle is titled Papyrus: The Invention of Books in the Ancient World.

How did you become interested in ancient books and the beginning of the printed word?
It goes back to my childhood. My parents were great readers and our home was bristling with books. I was fascinated by these rows of tiny black insects running across [the page] that only adults could interpret. And later, my studies of classical philology brought me into contact with the period when books emerged for the first time. And I’ve always been curious about the first times things happened.

In your book you say that as a child, you thought every book had been written for you and the only copy was in your house.
And I used to think my father was Homer, because he was telling me the stories from The Odyssey! My parents used to change the names of the protagonists of the stories [to] me or my friends. So I thought that all literature was written for me, and I was so disappointed when I discovered this was not the case.

Why is the great library of Alexandria so important in your book?
Alexander the Great was probably the first person to have a really global gaze on the world, and it was his idea to build this comprehensive public library that was open to everybody – even slaves and people from non-privileged families. So this was something different in the democratisation of knowledge. They wanted to gather all the books from all cultures and make them available for everybody. It was like the first step to the internet.

The original title for Papyrus in Spanish was El infinito en un junco (Infinity in a Reed). Can you explain?
It’s a metaphor for my description of what is wonderful about books. The idea that infinite feelings, experiences, fears and emotions can be [contained] in something so small and common. I’m thinking of the first books in history, which were papyrus scrolls [made from a type of reed]. It’s also a tribute to Pascal [Blaise Pascal, the French philosopher], who described human beings as reeds. He said we are fragile like reeds, but we have the power of learning and understanding.

What was the most surprising thing you learned when writing the book?
The biggest revelation in my research was the figure of Enheduanna – that the first person we know of who signed a text was a woman. She’s not in [textbooks] in high schools or university. I was studying classical philology for many years before I heard of her. It’s more difficult for a woman to enter the literary canon, and I wanted to make an effort to recover these names and fragments of poems or speeches, to recover the existence of these women.

Do you think that in our societies, where books are so easily available, we undervalue them?
Yes. We take them for granted, but there was a long story before this, of people facing dangers, sometimes dying, for books. And that’s the adventurous history I wanted to tell in this book. This is an essay about books and reading, but it’s also a huge adventure and I conceived it to be read with the same kind of thrill you get from a novel.

How has the success of Papyrus changed your life?
It was a huge surprise. In Spain you’re not expected to have success with essays, and also I wrote the book at a very painful personal period. Our son was born with a very serious health condition, with a long hospitalisation, and I wrote this book because it was therapeutic for me. [It] was born as a safe haven in those painful times. I wasn’t even sure that I’d be able to finish it. I didn’t know if anyone would publish it. And it’s had a totally unexpected reception – a lot of readers have embraced it, and my life has changed. All this happened during the lockdown, and it was so unexpected that a book about history, about classical philology, could be of some help in that difficult time. But somehow, readers found solace in my book.

How and where do you write?
Nowadays I’m not [working on] a big project because promotion is too demanding and I’m travelling all the time. So I’m just writing articles and taking notes, but I don’t have the calm or the time to start a new project. But since I became a mother, I got used to working everywhere and reading everywhere. Spoon in one hand, book in the other.

Which living writers do you most admire?
Mary Beard was a model for me, because she’s also a classical philologist like I am. She’s always breaking boundaries and defying the accepted knowledge about the ancient world. And she’s able to communicate with irony and a sense of humour. She’s a bestseller in Spain. I also love Tom Holland; his essays are very inspiring. I love Orlando Figes and Terry Eagleton. I love these books that are a border between fiction and nonfiction, and essays that have humour and irony. I’ve always been very much inspired by the tradition of British essays. I also love John Berger, and The Darkening Age by Catherine Nixey. This kind of essay isn’t very common in Spanish literature. We have the academic essay, but I wanted to use the skills I’ve learned as a novelist and [write] a kind of essay aimed at a wider audience. I think the most remarkable examples of these kinds of essays are written in English nowadays.

And if you could keep just one book from the ancient world, which one would it be?
My first answer would be The Odyssey, because it was the story [through] which I fell in love with literature. It’s essential for me. But I love so much ancient history: Herodotus or Tacitus. And Thucydides; he’s so insightful and useful for analysis of today’s world. So after The Odyssey, I would save Thucydides’s History of the Peloponnesian War.

• Papyrus by Irene Vallejo (Hodder & Stoughton, £25). To support The Guardian and Observer, order your copy at guardianbookshop.com. Delivery charges may apply.