Book of a Lifetime: Hunger by Knut Hamsun

I have a rough list of favourite books, which changes all the time. The book which had the greatest effect when I first read it is probably Hunger by the Norwegian writer Knut Hamsun.

It was published in 1890, when Hamsun was 30. He had been scrambling around for years, trying to write and to get his work published, failing over and over again, working in menial jobs, emigrating to the US for a near-fatal crack at the land of opportunity, returning to Oslo still more indignant about everything and determined to prove everyone wrong.

The never-quite-named protagonist is living and failing dismally in Oslo, "that strange city no one escapes from until it has left its mark on him". He tries to write, but no one really wants to pay him except the occasional kindly newspaper editor, so he has fallen into destitution and is almost starving. The novel follows him as he wanders around the city. He is in a heightened, almost hysterical state, intensely alert to the suffering of those around him as well as nearly demolished by his own predicament.

It's not just about being a failed writer. It's also about the process of entering adult life, that somewhat devastating moment when you realise that you have to work to live, unless you're obscenely rich; that you are obliged to exchange almost all your time for money. And how you might lose your ideals in the face of this unwieldy realisation. It's also about the social mask, how you are – in adulthood but even before – constantly being encouraged to conceal your real responses to things.

Hamsun's protagonist is quite childlike, because he refuses to adopt the ordinary disguises. So he disconcerts women with the force and honesty of his protestations of love, or works away feverishly on vast rambling articles presenting his philosophy, which no editor can publish. It's very funny in places, very dark, and then sometimes quietly poignant.

I was stunned when I first read it, in the great English translation by Robert Bly. Later I went to live in Oslo for a year, partly so I could learn enough Norwegian to read the original. DH Lawrence described being driven to write "out of sheer rage" and you get a sense that Hunger is propelled by Hamsun's anger – that he can't forge the life he wants, that he is starved of a congenial milieu for his writing. He knows also that such rage is inherently absurd, and yet is afraid perhaps of what happens if he stops feeling furious about things.

All the time you have a sense that he's being exceptionally honest, because he has nothing to lose. I also like the paradox of reading it now: that Hamsun was expressing a sense of acute isolation, both his protagonist's and his own, yet Hunger was his breakthrough work. As soon as it was published, Hamsun became a stranger to the life of hopeful desperation he so beautifully described.

Joanna Kavenna's novel 'The Birth of Love' is published by Faber & Faber