Paul Kalanithi, a neurosurgeon, was diagnosed with cancer at 36, months away from finishing his surgical training and his postdoctoral fellowship at Stanford University. From his wheelchair he wrote a memoir, When Breath Becomes Air. He died in March 2015 and 10 months later his book was published in the US, where it went straight to No 1 in the New York Times bestseller list. It is now out in the UK. Lucy Kalanithi, a doctor and academic, is his widow. LOK  Related: When Breath Becomes Air by Paul Kalanithi review – how to live, by a doctor who died aged 37  Has the book’s success surprised you?It’s exceeded our wildest expectations. A month or so before it was published it was getting some critical acclaim but the big question was whether people would actually want to read a book about dying written by a man who had recently died. We weren’t sure. But it turns out they do. I think it is because the book is about living as well as dying. And although it is about what happened to Paul it is also about a universal experience – and it is so beautifully expressed. That’s what people are responding to and holding on to.  How does it feel for you to see him so celebrated after – and because of – his death?Bittersweet is a vast understatement. But it is fantastic to watch him developing a legacy through the positive reaction. It is very meaningful to me. It’s just under a year since he died and it feels like no time at all: I still want to be thinking about Paul and talking about Paul, and having the opportunity to remember him in a communal way rather than in a lonely way is very helpful.  How would he have felt about the impact of the book?I think he would have been totally thrilled. His eyes would have been sparkling. He would have been so excited to be part of the conversation around the book because he was so interested in death and mortality.  How did you feel about him writing about your marital problems in the book?The bottom line is that I felt fine about it. I was surprised at first that he did it because Paul was a relatively private person and I thought of asking him to take it out but then I thought, no, it’s part of the story and it’s important to be authentic. People respond to authenticity and I felt like, OK, go ahead and share it. Now I feel glad it’s in there. It feels real.  There’s a heartbreaking irony in the way his cancer drew you back together and saved your marriage…I agree. But I think now that it was good timing because our problems came to a head and got out on the table right before he was diagnosed. I often wonder what would have happened if we hadn’t confronted our troubles when we did. As it was, we regained hope in our relationship and started to draw back together literally a week before he found out he had cancer. I think this meant we were in a stronger position to deal with it.  How easy was it to decide to have a baby when you knew he might not live long enough to be a father?Not at all easy. It was really very considered, as you can imagine. We certainly had our eyes wide open in that we knew it was likely that he wouldn’t live to see her grow up and I would go on to be a solo parent after he died. We first talked about it as soon as he was diagnosed but for a few weeks we were really unsure. We both had the instinct to do it but were both worried about the implications for the other one. I feared it might make his death so much more painful if he had to say goodbye to a child. But he said: “Well, wouldn’t it be great if it did?” His view was that life wasn’t about avoiding suffering, it’s about making meaning. It was obviously a big risk to have a child, to invite more uncertainty and possible pain in to our lives, but it was the best decision I ever made.  I knew that if Paul himself could have described the way he died then he would have done  Did you understand Paul’s decision to push himself back into work to finish his residency after his first bout of lung cancer?I did understand – because of knowing him the way I did. Not everybody would go back to work in his situation, many people wouldn’t. Everyone has different priorities and Paul endured a certain amount of physical suffering in order to work as a neurosurgeon and to write the book. But he was a natural learner, very driven and a deeply curious, impassioned person. Going back to the operating theatre underscored how much his work was a part of who he was.  Paul’s faith in God has surprised some reviewers. It is rare in a scientist. Do you share it?He was a top scientist but empirical research didn’t explain for him what it meant to be human. One time I asked him straight out, “Do you believe in God?” and he answered that he thought just as important a question was “Do you believe in love?”, to which his reply would be yes. I thought that was really striking. I would say the same thing.  Writing the epilogue for the book must have been hard for you. How did you approach it?The hard part was that I have never thought of myself as a writer at all. I’m a doctor: I can write a medical chart and express information. But I’ve never felt compelled to write an essay or anything longer. So when Paul’s editor asked me if I would consider writing an epilogue I was shocked. But I recognised that the story was unfinished and I knew that if Paul himself could have described the way he died then he would have done. I wrote it two months after he died, which was a very raw time and it was actually really helpful and I was so glad to have that opportunity.  Paul’s last paragraph is a beautiful account of the joy your daughter Cady brought him in his final months. What will you tell her about him?I’ll tell her lots of things but in a sense the book will tell her all she needs to know. Writing it was a way for him to communicate with her after his death. Through reading it and through things he left for her that I am keeping she will understand how much she was loved by him.  Related: Sign up to our Bookmarks newsletter  What does the future hold for you and Cady?People keep asking me, “Hey, are you going to stay in your house?” Well, I’ve made a decision not to make any decisions for at least two years. Our house is where Paul and I lived, then where the three of us briefly lived and now it is where Cady and I live. For me it’s now about reforming the space so I can move forward as a doctor, a widow and a mom. I’ve kept a lot of Paul’s things, but a few months ago I painted all the walls white and remade the bookshelves so that he doesn’t have his own bookcase any more, so I am slowly changing things.  At the moment of diagnosis Paul said he hoped I would get remarried. He meant it really lovingly but it was so shocking to me at the time. Now I feel that even if I do ever get remarried I am positive I will love Paul for my entire life. He will stretch into my past and into my future.  When Breath Becomes Air is published by Bodley Head, £12.99. Click here to order a copy for £8.99
The doctor on completing the memoir of her late husband, surgeon Paul Kalanithi, after he died of cancer