Your first novel was about failure, and your new book is a memoir about having and losing it all. Can failure enrich people?

I think it can, in that it burns away all of your illusions. There is a sense in which failure is necessary because so much of the what the world says to us is that you must succeed, you must acquire, you must have your house and your kids and your cars, and your professional achievement. But I think that what failure says is that there are other things to care about.

There has been an increase in failure memoirs written by men in recent years (Toby Young, David Shields, David Goodwillie, Greg Baxter). Why is this?

This is probably changing, but one of your responsibilities as a man – and it's instilled in all of us from an early age – is that you go out into the world to achieve and provide. Granted I had different models with my own family since my father was such a counterculture type, but it was still instilled in me that I was to go out into the world and win. So when you can't and you fail, it becomes this great burden. Something of your manhood has been reduced. I did feel it quite acutely when my son was very young and I was out of work, and I would pick him up from daycare and we'd go to the park and the only people there were women, there were no dads. I felt I was suspect in the eyes of the women. In three years no stranger ever talked to me …

Do people think failure is infectious?

Oh yes, they absolutely do. I didn't write about it but when I was going through my divorce and my publishing and financial problems there were certain members of the publishing community in New York who just pretended I wasn't there. Failure is a real abiding fear for a lot of people. If you are marked with it, it can be doubly isolating – not only are you dealing with it every day, but other people do turn their backs on you.

Did you always know you were going to be a writer? Is it your vocation?

I always suspected it. I was very interested in politics and social science but I fell into writing the way a lot of people do – everything else either doesn't work, or you lose your interest and you're left with you and the page. But what I've learned is that you can practise your vocation while doing other things. Facing real failure like I did can help you reformulate the way you approach life and it did help me dispense with a lot of illusions – like writing is so vitally important it crowds out everything else. The status I gave it made it impossible for me to write well – I was under so much financial pressure I couldn't think clearly.

You amassed a large amount of debt. Eighty thousand dollars, wasn't it?

Oh, it was more than that. I didn't write about this in the book, but I was going through some pretty serious medical stuff [complications arising from a brain tumour he had at 21] and I didn't have health insurance – I had an additional $100,000 of medical debt, just to stay alive …

How much of your creative energy was taken up with phone calls from debt collection agencies?

Whenever I was at rest that's where my imagination would go. How am I going to deal with paying my credit cards, the friends I'd borrowed from, how am I going to make my child support payment next month? It's hard to write about imaginary characters and their inner lives when you're dealing with these problems.

Yet you write with a large dose of self-deprecating humour.

To me humour is the key to understanding. I get very agitated when I'm reading a book that is humourless. Even if it's beautifully written if there's no sense of humour it's a sign the writer doesn't have any sense of perspective.

Is there any part of the book that you feel leaves humour behind and moves into bitterness and anger, maybe even self-pity?

Sure. One of my greatest goals in writing the book was to leave this Too Good to Be True persona behind. When I wrote the chapter that's the letter to the Nominee [his ex-wife's new partner] I didn't know I was going to keep it, but in a lot of ways it's the climax of the book. So yes, there is some self-pity, there is some smallness [laughs].

Was writing the book painful or therapeutic or both?

It started out being both, but once I realised I was writing a book, it became like any other book – just this problem you're trying to solve. I managed to put my personal failings aside and just think about it as a piece of artifice I was trying to bring to life. How to make a narrative arc out of a life that was still unfolding before my eyes. I didn't know whether or not I was going to find a job, if I was going to stay with my girlfriend. I didn't know where I was...

You had a fling at a book fair. Do you regret coming clean about your infidelity?

I think telling my wife was a big mistake. It was a very selfish thing to do. I had a hard time dealing with the burden of it but I should have worked it out. The few people who did know about it said "whatever you do, do not tell her". It's sad, but in some ways the key to any long-term relationship is that you don't tell. Obviously if you're in a relationship and you keep on cheating there's a problem. But if it's a one-shot deal I don't really see why you should tell.

So if you did it again you wouldn't tell your partner ?

One of the things I've realised is that infidelity makes me miserable. So I don't see that happening.

What do you think when you meet people who are genuinely contented?

I think, my God, what's their secret? I live in New York, though, so I don't meet people who are contented. Everyone I see looks like they're carrying their mortgage in front of them in a wheelbarrow. The burden of life is astounding.

You give a vivid impression of how hard it is to make a living as a writer. If your son came to you and said he wanted to be a novelist, what would you say?

That is my greatest fear! When he was three, I got a shower curtain that had a table of the elements and I tried to get him reading as many science-related books as possible. Chemistry, physics… basically all the things I never understood. But if he does come to me and say he wants to be a writer, what can I do other than to say, that's wonderful.