In This Boy's Life, Wolff forges the school reports and testimonials that help win him a scholarship to a top private school, tries to cash dud cheques, steals from the homes he visits on his paper round and pawns his stepfather's prized guns, knives and binoculars. He was on course to self-destruct and then he joined the army, that refuge for those who want someone else to take control of their life. These are the years of the second volume, In Pharaoh's Army, which has just been published in paperback. He spent 1966 in Vietnam and lost his best friend there. He got to know his father again having scarcely met him since his parents split when he was five years old and finally, by one of the extraordinary strokes of luck that repeatedly befall him, he ends up, barely educated and without qualifications, reading English literature at Oxford.
What struck a chord with readers when This Boy's Life was published in 1989 was how candidly Wolff shows himself throwing trust and kindness back in the faces of those who offer it. At times he appears to have the emotional emptiness of a psychopath. Instead of the autobiographer casting himself as hero, Wolff is the villain of his piece. That atmosphere of alienation led to the book being made into a film, released here last year.
Wolff is scathing about any other kind of autobiography. "Some writers embark on memoir as a means of self-promotion and self-justification, a picture of themselves as the besieged vessel of virtue, buffeted by an unkind and uncomprehending world," he says. "It seems fundamentally skewed to me. See yourself as part of the whole hurly-burly of the world you're writing about and equally susceptible to the temptations and corruptions that beset others. We're all complicit in this deal."
After Oxford, Wolff was briefly a reporter on the Washington Post. Another lucky break: he met the editor at a party and just asked for a job. He threw that up for San Francisco, where he worked at night as a waiter ("I usually got fired after a week and a half") while writing by day. The breakthrough was having a story, "Smokers", published in the magazine Atlantic Monthly.
His style was described by the literary magazine Granta as "dirty realism" in the American tradition of Raymond Carver and Richard Ford. Later, his memoirs earned Wolff the "male confessional" tag in Britain. He has written one novel, The Barracks Thief, an examination of the peculiar pressures on friendship of military life.
It is unusual for a writer to make his name with memoirs before really being famous for anything else but Wolff says the books grew out of autobiographical sketches that he composed as a bank of anecdotes for his fiction. "They took over," he says, "and I put my short stories aside."
His eyes still widen in appreciation of the luck that hauled him out of a drifting, drinking abyss, not once but several times. His own brother, Geoffrey, played a considerable part in this. Geoffrey's life was the antithesis of his little brother's. Seven and a half years older than Toby, he was brought up by his father and did well at a top private school and Princeton while Toby and his mother moved around, landing themselves with unsuitable stepfathers.
Now he says: "That was an almost unrelievedly dark period in my life. I was on the scrapheap at 15, I couldn't see what was going to happen to me, I was so used to defying and to defining myself in opposition. When someone said 'Do A,' I would instead do B."
Although Wolff had not seen his brother for years it was Geoffrey who encouraged him, by letter and telephone, to apply for a scholarship to get away from his stepfather, not realising that his young brother's description of sporting prowess and straight A grades was a pack of lies. Wolff was eventually expelled for compulsive rule-breaking.
Unusual for their jarring frankness, the memoirs also buck convention in not including the standard sexual rites of passage. Perhaps he did not chase girls to the same extent as other boys? "0f course I did," Wolff snaps, irritated. "I had to make a decision about that and I didn't see anything particularly noteworthy in it. The engine that drove me was feelings of class anxiety, status anxiety and powerlessness. That sexual ground has been well covered. What I did have was a calculating ambition which was unusual in a boy."
But he let his chances slip away? "Yes." He pauses for a moment. "When I got to the school I didn't want to be one of the drones, which was what all the working-class scholarship boys were expected to be. My ambition got translated into how I saw myself with others." (This obsession with class is curious in an American. Clearly, even as a teenager, Wolff had worked out that his countrymen's dream of equality and opportunity for all was a myth.)
And 35 years later, Wolff still won't allow himself to be seen as trying too hard to please. The coldness and defensiveness in his manner is odd in someone who has already laid bare so much of himself in print.
In Pharaoh's Army is a collection of individual pieces describing episodes of his life, from the ages of 18 to 26: vignettes from his year in Vietnam ("the worst year of my life"), how he came to spend four years in the army, and his training as an officer. Bizarrely, considering his past record, Wolff was deemed to be officer material because he had "command presence". When he left the army, there was a stay with his father who was not long out of jail for passing dud cheques - he had tried, incredibly, to use the name Sam Colt (inventor of the revolver).
What makes the book differen t from all the others written about Vietnam is that its events have been chosen to tell us not about the war but about Wolff and his reactions - to fear, to deprivation, to loss. "The cohesion in that book is that it is about survival," Wolff says. "Physical survival in Vietnam and also about the survival of one's emotional life and the capacity for affection and friendship."
If the alienation is unremitting in This Boy's Life, there is more humour in In Pharaoh's Army and more about compassion and loyalty, for example, his desire to avenge the unspoken racism endured in Vietnam by his black sergeant. This anger takes him back, alone, to a red-neck bar in Saigon to provoke a beating and thereby suffer pointlessly for a colleague who will never know of his gesture.
The subject of war is a constant source of fury to Wolff. "It's the same damn thing all the time," he rages. "It's always vain ego-maniacs who will never be touched by what happens, who get these things started and then these ordinary little people, who get called Serbs or whatever, who are just farmers and who just want to live, get stepped on."
So why did Wolff subscribe to the war ideal by volunteering for the US army? "It's funny, I'd read a lot about war but I wasn't really getting what they were saying which was 'Don't do it'. The message I got from people like Hemingway, was 'I had this life and I ended up a writer'. This is what you have to do." Wolff laughs. "I was subject to the myths."
The publication in 1975 of the first of his many short stories brought him an agent, a fellowship at Stanford University and the sort of status he had longed for since the age of 10. From there he taught in Arizona before making his move to Syracuse in 1980.
He lives with his wife, small daughter and two teenage sons. He says his memoirs have helped rather than hindered his relationship with his boys. "There's a natural inclination for parents to don the robes of rectitude. My boys know that I can't pretend that's the case and it puts us on a more realistic footing with each other, I think."
Wolff was in Britain last week to help judge the Esquire/Apple/Waterstones annual non-fiction award, which he won last year for In Pharaoh's Army. Which writers does he most admire? "Whoever I'm reading at the moment," he says rather testily.
The photographer arrives to take the pictures for this piece and while she pulls out her camera we haggle briefly over how much more time he will allow for the interview. Half an hour? "No, 15 minutes," he says, firmly. (Ten minutes later he warns: "I'm coming to the end," command presence bristling.)
He is working on a new collection of short stories, written on and off over the past 10 years, and has another novel in mind. He says the stories, which he would like to call Bullet in the Brain but which are more likely to go out under the less challenging title of No Place Like Home, have a "bite and poetry" that he is pleased with. He has declared there will be no more autobiography. But, he says now, "All stories are autobiographical if they're any good because they arise from your take on the world. Sean O'Faolain has a great line - he says all good writing is the writer arguing with God. Which means it's the beef. When I write, I not only air my beef but I discover what it is. Ideas become apparent that I didn't even know I had."