My earliest reading memory
One of the most intriguing books, when I was around six years old, was Gangles by Ronald McCuaig. The main character, a wild girl from Australia, could stand on top of fountains and travelled around with a whale by balancing on the water spray the whale exhaled. Reading that book was one of the great experiences of my childhood. That is completely impossible to understand when I leaf through it now: how could something so small grow into something so huge? Pure magic.

My favourite book growing up
A Wizard of Earthsea by Ursula K Le Guin. No one above, no one beside. I must have read it 10 times in my youth. A young boy with wizard abilities goes too far out of hubris and lets an evil creature into the world. From then on it chases him, until he faces it and calls it by its true name, which is his own – what more could an 11-year-old desire to speculate over?

The book that changed me as a teenager
The History of Bestiality trilogy by the Norwegian author Jens Bjørneboe. It is about the evil inherent in human beings, and goes through history’s wars, massacres, oppressions and torture methods. I was 16 when I read it, and it felt like the truth about humanity had been revealed to me. I lived alone with my mother at that time. She is an extremely patient person, but after hearing me go on about how terrible everything was night after night, she finally snapped: she started laughing. I have never been so offended in my entire life. I can still hear that laughter, and sometimes I laugh myself (inside, though).

The writer who changed my mind
My whole reason for reading is exactly that: I want my mind changed! I’m desperate for new ways of looking at the world. The writer who has given me that most profoundly is Jorge Luis Borges, especially in my all-time favourite short story, Tlön, Uqbar, Orbis Tertius. It is about how the world reflects our thoughts about it, that we see what we know, not the other way round.

The book that made me want to be a writer
I loved sea adventure novels when I was young, and after reading Percival Keene by Frederick Marryat, I decided to write one myself. I was around 10 years old. The novel began by listing everything on board the ship, and when I gave up after maybe 15 pages, still nothing had happened. (But that wasn’t why I gave up, it was because my brother said that nobody wrote books about sailboats any more.)

The book or author I came back to
To the Lighthouse by Virginia Woolf. I read it at university and I didn’t understand much of it. I saw it primarily as an example of modernist prose. When I read it again a couple of years ago, any belief that Woolf’s language created distance from her characters and their lives was turned on its head: everything is shockingly close in that novel! The here and now is released, the moment we live in before there is a narrative, before the story shapes it into something else.

The book I reread
The first time I read Tolstoy’s War and Peace, I was 19. The second time I was 29. The third, 44. It is my absolute favourite novel. In 10 years, I manage to forget everything in a book, so it’s like reading it for the first time every time. Unfortunately, it is not the case that I see something new in it as I get older. On the contrary: when I was 29, I talked the head off another author about War and Peace. By chance, I met him again when I was 44, and according to him, I said exactly the same thing about the book in exactly the same way. But for me, everything was new …

The book I discovered later in life
I once watched a TV interview with a Swedish author who said that Turgenev’s Sketches from a Hunter’s Album had more or less saved his life. It is difficult to find a stronger recommendation, so I read it, and understood what he meant. It is outstanding, simple and unaffected; one of the few books I have read that allows the world to come to it.

The book I am currently reading
Judith Hermann’s We Would Have Told Each Other Everything. A treasure of a book by one of the best writers around.

My comfort read
Spy novels.

The Third Realm by Karl Ove Knausgård is translated by Martin Aitken (Harvill Secker). To support the Guardian and the Observer buy a copy at guardianbookshop.com. Delivery charges may apply.