There is a houseplant, the hanging saxifrage, that in German is known – or used to be known – as Judenbart, “Jew’s beard”. This is not to be confused with the species of tradescantia still known in English as “the wandering Jew” – Google it, and you will find articles of advice for gardeners with unselfconscious titles such as “methods for the control of wandering Jew”. The Judenbart is mentioned twice in Walter Kempowski’s An Ordinary Youth, first published in 1971 and now appearing for the first time in English translation. The book – whether or not it is right to call it a novel is one of the many questions that it poses – consists of continuously relayed fragments of Kempowski’s youthful memories from the late 1930s to the fall of Berlin.

The gradual triumph of nazism is made to creep up on the reader as it did on the young narrator. When the operations of genocide appear they suddenly punctuate his experiences, jutting into the narrative: “On the way to school we passed a narrow house… Two Pekinese dogs were always lying in the window. When they saw us they started yapping like mad. Beside the house was a burnt-out synagogue, with a broken Star of David on the wrought iron gate.” The narrator’s friend tells him that a severed finger was found there, and a basement crusted with the blood of murdered Christian children. Such moments are, however, the exception, rifts in a calculatedly even and placid narrative style. What is the relation, the book asks, between such acts of violence and everyday facts such as the naming of the Judenbart – a name that subtly associates Jews with plant life (green beans in Spain are still called judías verdes, green Jewesses), and with the straggly beards that were said to hide their animalistic faces and through which they muttered their incomprehensible prayers? (I write this as, myself, a relatively lightly bearded Jew.) Do these everyday choices, the ways in which hatred and fear are woven into ordinary language, help to explain the obliterated synagogue? Do the war games that the young narrator plays with his friends, in which “garden peat” stands in for “the brown soil of Poland”, prepare them for their activities with the Hitler Youth and then the army? But if racist language and bellicose children’s games are everywhere, how can the appalling distinctiveness of the German case be explained?

Kempowski posed these questions throughout his writing life, blurring the boundaries between fiction and documentary in his novels and in his massive compendium of wartime documents and memories, Das Echolot, an extraordinary marshalling of collective recollections and complicities. The translation of An Ordinary Youth at this particular moment in time, however, half a century after its original publication, also feels like a reflection of contemporary tastes. This is, it must be acknowledged, frequently a tedious book, one that asks its reader patiently to endure the succession of snapshots that it provides, lulled into a kind of mild torpor from which they can periodically be jolted. This may in part be a function of the translation: Michael Lipkin’s translator’s note observes that the impossibility of capturing the “distinctive opacity” of the original has resulted in a version that “looks rather a bit more like ‘a bourgeois novel’ than does the original”. In any case, the translated version is a book that invites the reader to become bored, and to become interested in, to reflect upon, their own boredom; to wonder how horror can find itself at home amid the ordinary. As a reading experience it is less close to another great and far more sickly and surreal attempt to see the rise of nazism through a child’s eyes – Günter Grass’s The Tin Drum – than to more recent literary successes such as Karl Ove Knausgaard or the Nobel prize winner Jon Fosse, whose immersion in minutiae and exorbitant demands upon their readers’ attention spans seem designed to electrify and infuriate by turn.

I began reading Kempowski’s book before the horrific scenes of Hamas’s atrocities unfolded in Israel. By the time I finished it, the barbaric bombings in Gaza had become a sickening backdrop to everyday English life; I also felt the need to tell my young daughter, to whom a Star of David pendant had been sent in a misguided gesture by a non-Jewish relative, that this was not a safe time to start wearing it in public. This book feels horribly timely as a renewed posing of the question of what horrors we are willing to accept as normal.

• An Ordinary Youth by Walter Kempowski, translated by Michael Lipkin, is published by Granta (£18.99). To support the Guardian and Observer order your copy at guardianbookshop.com. Delivery charges may apply