Günter Grass kept silent for 61 years about his service in the Waffen-SS, the combat unit of the elite Nazi paramilitary force that ran concentration camps. His autobiography, “Beim Häuten der Zwiebel” (“Peeling Onions,” Steidl Verlag, 480 pages, 24 euros), just published in Germany, aims to tell all.

Frustratingly, it doesn’t. There is a lot that Mr. Grass, now 78, doesn’t remember. After suppressing so much for so long, he appears to have successfully banished much of his early life from his memory altogether. He establishes such a distance from his young self that he fails to make the child and young man that he was either convincing or appealing.

It’s likely Mr. Grass, who did not kill or injure anyone during the war, knew his belated confession would cause a stir. More than the Nobel-Prize-winning author of “The Tin Drum,” he is Germany’s national poet, the voice of its postwar conscience. His opinion is sought — and given — on everything from art exhibitions to military operations in the Middle East, from compensation for Holocaust survivors to the power of capitalism.

After he disclosed his Waffen-SS past to the Frankfurter Allgemeine Zeitung on August 12,a storm of recriminations and an outburst of hand-wringing quickly escalated. Among the more extreme demands were that Mr. Grass give up his honorary citizenship of the city of Gdansk and his Nobel Prize. Meanwhile, fellow writers rushed to his defense.

In his waning years, Mr. Grass has every right to reflect on his past and try to come to terms with his own war guilt. Being who he is, it is also inevitable that his confession will be combed over in the media. But Mr. Grass is old and he was young during the war — the last generation who remembers it.

Perhaps — one can hope — this will also be the last time that self-flagellation and collective soul-searching over the Nazi era return to the front pages. It is a debate that, though inevitable and necessary, keeps Germany from looking forward.

Amid all the uproar, Steidl Verlag brought forward the publication date by two weeks and the book is flying off the shelves. Yet as a tell-all confession — and as an insight into Mr. Grass the man and the artist — the memoir is disappointing.

It starts with the beginning of the war, when Mr. Grass was 12 and growing up in Gdansk — then Danzig — and follows his life through the war years and his injuries, his experiences as a prisoner of war during the chaotic aftermath, his years as a stone mason and sculpture student in Dusseldorf, and his transition from sculptor to poet after he moved to Berlin.

Mr. Grass’s father joined the Nazi party in 1936, “when pressure to do so in Danzig was still only moderate.” Mr. Grass remembers, at the age of 12, watching curiously as a horde of storm troopers plundered, destroyed and set fire to a synagogue.

“As a member of the Hitler Youth I was a young Nazi,” he says. “A believer until the end.”

Yet he remembers very few details about volunteering for the submarine service and doesn’t recall the wording of his conscription order, nor when he first realized that the unit he joined was a part of the SS. His main motivation for volunteering, he says, was to get away from the claustrophobia of his family’s two-room apartment.

While chastising his young self for not asking the right questions and for failing to doubt the Nazi regime, Mr. Grass prevaricates. His overuse of metaphor — particularly the central image linking memory with peeling an onion to get to the truth even if it causes pain — leaves you with the impression he is trying to avoid getting to the point.

He opens by saying he is tempted to refer to himself in the third person as a disguise, then does so on several occasions — an admission that he can’t fully accept his former self.

The alienation at times stretches to an almost schizophrenic resentment of his young self for burdening his older self with guilt. Mr. Grass will not resort to blaming his environment, his family, the turbulent times, or even his youth for his belief in the Nazi ideology. He has been too critical of the excuses of others to make any for himself. So he blames himself — his young self.

That makes for uncomfortable reading. Contemplating his young alter ego, he says:

I am now elderly, he is unashamedly young; he is looking to the future, the past is drawing me backward; what preoccupies me now doesn’t worry him. The things he doesn’t want to be ashamed of are left to me, as more than just a relative, to deal with now.

When he can’t remember exactly what happened — for example, in saying goodbye to his father at Danzig station as he heads off to war — he offers alternative scenarios in the form of questions that are just frustrating. “He embraced me. Yes, I am sure I embraced my father. Or were there just manly handshakes?” And so on.

What makes the book worth reading are the vignettes that evoke those terrible and chaotic times — the vivid descriptions of trains passing through burning cities and the colorful characters met on the way. One is a woodenlegged pipe smoker who sticks a knife into his leg to silence a woman’s complaints that he is polluting a non-smoking compartment.

The most brilliant comic passage in the book is pure joy — a description of a theoretical cooking course, taken by a Bessarabian chef, that Mr. Grass attended in an attempt to still his hunger pangs at his prisoner-of-war camp in Marienbad.With no ingredients and no tools save chalk and a blackboard, the chef summons up steaming platters of pork and meaty soups that make the mouths of his students water.

Mr. Grass is a wonderful storyteller, and “Peeling Onions” would have been a more entertaining read if he had stuck to that, leaving others to cast judgment on his young self.

It is almost as though, having taken on the role of his country’s moral authority as well as that of its best-known living novelist, he had to make sure he was the first — and possibly the harshest — judge of himself.