Whatever your knowledge of Karl Ove Knausgaard’s internationally celebrated My Struggle sequence, its third volume is likely to surprise. For those already immersed in Karl Ove’s meticulously rendered life story, Boyhood Island is a departure in structure and purpose. For those yet to read him, it may be a question of wondering what all the fuss is about. It is testament to the power and immediacy of Knausgaard’s writing, however, that both camps are ultimately rewarded with a subtle, burning sense of the lost years of childhood.

The previous novels – A Death in the Family, A Man in Love – are direct in approach, but complex in their structure: Knausgaard looking back on his life, framing his experiences with older eyes, while never forgetting that his past actions belong to another life. This approach is abandoned in Boyhood Island in favour of a straight narrative, told almost entirely chronologically, through the eyes of a growing child.

It’s a gambit that initially feels a little lightweight, somewhat obvious. The superreal detailing of life employed in the first two books is matched by dramatic tension and a sense of an overarching struggle with the self; yet in the opening sections of Boyhood Island this narrative propulsion seems lacking. Without the breakouts and disjointed chronology, the encyclopaedic exploration of a boy’s humdrum life can seem somewhat wearying and meandering. It takes time for the voice to work on the reader, to suck them into the unguarded thoughts of a boy turning into a youth.

While we cycle through the usual tropes of coming-of-age fiction – school, play, parental issues, body worries, sex, fear – Knausgaard constructs a voice that is both convincing and utterly convinced of its place in the world. This is where the “true” Karl Ove resides, in this arrogant yet cry-babyish boy, in his devotion to both the physical world of football and swimming, and to the imaginative world of comics and books.

Read in context of the sequence as a whole, Boyhood Island lacks the sheer transformative power of the previous volumes, but delivers a vital piece of Karl Ove’s struggle: a struggle to know himself as well as he did as a child. Read in isolation, it is a striking and cumulatively engrossing addition to the literature of childhood. In both cases, Boyhood Island is a vital, uncompromising, occasionally patience-trying attempt to resuscitate the ache, frustration and pleasures of growing up.

Boyhood Island is published by Vintage (£8.99). Click here to buy it for £6.99