There are perhaps more relaxing preparations for interviewing Neil Young about his autobiography than reading Neil Young's autobiography. It's not that Waging Heavy Peace isn't a good book. It is, albeit in a very Neil Young-ish way. Over the course of its 500 pages, Waging Heavy Peace is variously wildly idiosyncratic, unpredictable, bafflingly digressive, wryly funny, deeply moving, plain-speaking, still in thrall to the mysticism of the late 60s, painfully honest – "do not doubt me in my sincerity," counsels Young at one point, "for it is this which has brought us to each other now" – infuriatingly elusive and shot through with moments of rare insight and beauty, which you might say makes it the perfect literary counterpart to the 50-year career it describes, in a fairly roundabout way.

Anyone hoping for a chronological hop through Young's triumphs – the astonishing run of albums that stretches from 1969's Everybody Knows This is Nowhere to 1979's Rust Never Sleeps, the supergroup Crosby, Stills, Nash & Young, his early 90s resurgence, borne by the alt-rock scene his music inspired – is going to go home very disappointed indeed. The main criticism of it is that it has a tendency to ramble, but as fans at Crazy Horse's recent show in New York's Central Park would have told you – perhaps as their version of 1991's Love and Only Love entered its 14th minute, with no sign of a conclusion in sight – Young is an artist who has always reserved the right to ramble on a bit.

The problem, at least for the prospective interviewer, and particularly if the interviewer is a huge, hawkish Young fan, comes when you reach the part where Young reveals his feelings about interviews. "I hate interviews," he offers, fairly unequivocally. Journalists, meanwhile, are "jerks" and "dickheads". He is specifically referring to the journalists from Associated Press present at the infamous mid-80s interview when Young – he of the peace signs on his guitar strap and the song about how he never knew a man could tell so many lies until he saw Richard Nixon – appeared to voice support for Ronald Reagan. But you somehow get the feeling it extends to the profession as a whole. Still, at least the prospective interviewer can console himself with the fact that he's not a blogger, by contrast with whom journalists appear to be his favourite people in the world.

Still, crackling down the line from his New York publisher's office, the 66-year-old sounds affable enough. If I never exactly get the impression that talking to me is the highlight of his day, at least it's nothing compared with some of the stories that circulate among quaking hacks who have made his acquaintance over the years.

It might help that I can't see him: Young's eyes apparently have a habit of fixing journalists with a glare that causes them to wake in a cold sweat years after their encounter. "Back in the beginning I was averse to doing press because I'm not really comfortable with reading about myself," he offers. "It pisses me off that I can't just create art and have the art stand on its own. I would say, hey, if it's a great album it's going to sell … If it sucks, you know, no one's going to buy it. If it's mediocre, some people will buy it, or it could be great and nobody will get it. But it doesn't make any difference what you say about it."

Nevertheless, he says, Waging Heavy Peace isn't intended as a rebuttal, a misunderstood artist setting the facts straight: he professes not to care about the shelfloads of books that have already been written about him. "There's nothing much I can do about it and it doesn't matter to me. I find it of interest just to look at it and go, hey wow, that's something else. What am I going to do with it? I don't know what to do with it."

In fact, the book seems to have very prosaic reasons for existing. "Writing is very convenient, has a low expense and is a great way to pass the time," he tells the reader at one juncture, with admirable candour. "I highly recommend it to any old rocker who is out of cash and doesn't know what to do next." Young needed the money, because he appears to spend it as fast as he earns it. Not, it should be noted, on rock star fripperies, but on vast, complex non-musical projects about which he talks at length in Waging Heavy Peace: his Lincvolt electric car, his inventions for model railways, and his proprietary music system Pono, an iPod rival he says delivers perfect studio sound quality.

He had the time because he broke his toe and was unable to play live: "My manager had mentioned that Penguin was interested in me doing my memoirs, but I hadn't thought much about it. But then when I broke my toe I was just sitting there going, what am I gonna do now? I thought: why don't I just do that book?"

To compound matters further, the author of Homegrown and Roll Another Number for the Road had given up smoking marijuana and drinking alcohol on his doctor's advice: he suffered a brain aneurysm in 2005, the same year his father died after a long struggle with Alzheimer's. He says that he had barely written a song in 40 years without smoking weed: according to the book, he had literally never performed with his most celebrated backing band Crazy Horse straight. Waging Heavy Peace is underpinned by a struggle to connect with his muse without the aid of a smoke. Given that he is about to release his second new album this year, it's a struggle he clearly overcame. Arriving hot on the heels of Americana, which featured Young and Crazy Horse singing the British national anthem, Psychedelic Pill opens with a track that clocks in at nearly 28 minutes: clearly Young's cranky eccentricity has survived sobriety intact. In Waging Heavy Peace, however, there are moments when Young openly wonders if he'll ever complete another song. "How fucking loose do I have to be to write a song?" he protests at one point.

"I was never really worried about it, other than I was curious about it, in a day-to-day way," he says to me. "I'd go, wow, I've not written a song in a long time. This is very different. " As it turns out, he didn't need marijuana to write songs at all. "I didn't know at the time what was going to happen so I was discovering it, and now I've discovered that it doesn't matter."

The book frequently turns up a fascinating nugget of information about a well-worn story from Young's career. He is wryly amusing about his mid-80s battles with his record label, which ended up suing him for making music "that was uncharacteristic of Neil Young": "I don't," he says today, with charming understatement, "react well to being told what to do." If it doesn't tell a fan much they don't already know about the demise of Crazy Horse's guitarist Danny Whitten, whose death from an overdose at 29 spurred Young to convene the drunken, grief-stricken recording sessions for 1975's astonishing Tonight's the Night, it does reveal that Joni Mitchell showed up during said sessions, proceeded to get as plastered on tequila as everyone else, then delivered what Young thinks is the greatest performance of her career: much to his chagrin, she refused to release it.

The book also acts as an index of Young's obsessions, some of which, it has to be said, are more expected than others. He writes beautifully and very movingly about his wife and kids, not least his son Ben, born quadriplegic and with severe cerebral palsy, who Young calls his "spiritual guide". "You can feel him," he says. "He doesn't talk, so it's very spiritual, very brain-to-brain, soul-to-soul, and it's very refreshing and rejuvenating."

Equally, he spends an unexpected amount of time discussing Human Highway, the 1982 film comedy that he directed and starred in alongside Dennis Hopper: it cost Young $3m to make, and even his devoted fans tend to find it a bit of a schlep. He returns again and again to the truncated career of his and Stephen Stills's mid-60s band Buffalo Springfield, which he seems to regard as unfinished business. "It just seemed like it never reached its potential. There was always something wrong, always somebody missing, always some kind of conflict, always a problem. It stopped us from being as great as we could be, and we didn't know how to deal with it and so we really didn't quite succeed."

Some people would say the same thing about Crosby, Stills, Nash & Young, the early 70s supergroup torn apart in their prime by drug problems and ego, but Young insists Buffalo Springfield were different. "The Buffalo Springfield … we lost our players, we didn't lose our minds. We lost our bass player" – the late Bruce Palmer, who got deported back to Canada in fairly spectacular style after driving down the Pacific Coast Highway on LSD without a licence. "We lost what made us great, and when we got the chance to record with the band in the first place we didn't have anyone good to take us into the studio and make the best of what we were. Two of the guys are no longer with us, so it's difficult, but we're yet to do something that …" His voice tails off. "You never know."

In fact, Young writes with great affection for the late-60s hippy era, something that might come as a surprise to long-term fans. It was Young, after all, who spent his 1972 tour literally screaming at his docile hippy audience to wake up and realise that the utopian dreams of the Woodstock nation were dead, and that they had been bullshit all along. "You can live your own life/ laid back and laughing?" he howled on 1973's Last Dance, before singing the word "no" 60 times. A year later, he released the gripping Revolution Blues, which brought up the spectre of murderous hippy Charles Manson, whom no one other than Young really wanted to discuss: Crosby, Stills and Nash asked him not to perform it onstage. And yet, here he is, reflecting fondly on the clothes and drugs: he even seems quite affectionate about catching the clap. "Well, those songs were reactions," he says. "It's just disillusionment with the original idealism and naivety." Has time softened that disillusionment? "Well, perspective changes it. Not softened." He laughs. "It's just less in my face."

Perhaps his affection had its roots in the enjoyment he clearly got from writing the book: reading it, his enthusiasm for the project is almost tangible. "Well, it's always good to be doing something for the first time. There's no pressure," he says with an unmistakable wistfulness: in the book he keeps returning to how carefree he was in the early days of his solo career or Crazy Horse, before he was competing against his own past, before he had a vast, hugely influential back catalogue for his new music to be compared with. "Well, there's the pressure to do something people feel is worthwhile, but other than that there is no pressure."

Indeed, he enjoyed it so much, he is already writing another book, this time about cars. "I do it really easily. I could probably do this and just this for the rest of my life, and I would be OK." But no, he says, there's no danger of that actually happening: much as the reader might get the impression he is currently more interested in electric cars or music players than music itself, he insists they're not taking over his life either. "It gives me relief, it gives me something else to do so that music doesn't wear me out, so that I don't wear the music out. Everything should be taken in its own dose. You don't want to OD on music and then the music loses its potency. If that's all I did, it wouldn't be as good. I think if you don't have some obsession in your life, you're dead."