When I was 18, I was in a car accident: a girl swerved in front of my car, I couldn’t avoid her, and she died. I moved soon afterward, and so this crash and its aftermath made up the secret I carried around for 18 years. Until I wrote Half a Life.

40,000 die on US roads every year. And with every accident, somebody walks away feeling he’s put on the executioner’s hood. That’s one reason Half a Life has resonated with so many people. But it’s not the only reason, I’ve come to realize.

When I decided to write this story—the story of me and of the girl who died that day—I don’t think I understood how universal other people would find it; I was just writing what had happened to me. But very soon, I realized this story threw huge shadows. Excerpted in GQ and on This American Life, as well as in The Times of London, The Daily Mail (UK) and numerous other publications in the US and around the world, Half a Life ended up having real valence for a great many people. I’ve received probably over a thousand emails from readers who have wanted to share their own stories: a man who blames himself because he didn’t take his mother’s threats seriously and therefore left for boarding school the day before her suicide; a number of soldiers back from Iraq and Afghanistan who are dealing with post-traumatic stress disorder; people who have suffered horrible personal loss; and, of course, many car accident survivors.

Furthermore, I traveled the country with this book—even before it won the National Book Critics Circle Award for best memoir/autobiography of 2010—and at every reading I gave, someone invariably came up to me and shared a story of personal grief and guilt. At first, I didn’t know why they were opening up in this way: what did seeing one’s brother overdose have to do with my story? And why did this person want to tell me?

When I was a kid, after the accident, I felt completely alone—suffering under a crushing guilt, even though everyone said I wasn’t at fault.

The thing is, no one knows how to feel about guilt: people think if an official person—a policeman, a judge or reporter—says you weren’t at fault, it’ll be all right. What the book is about is: that’s not so. If you just accept what other people tell you to feel, it leads to your living half a life, with the other half covering something up.

The point is, it turns out almost everybody has something in their past to feel guilt and/or grief about, whether they were culpable in their life-shaping event or not. It doesn’t have to be as dramatic as mine. (I was found blameless in my accident, but that didn’t stop the lawsuits from happening.) Everyone is worried about doing what appears to be right, rather than what is right for them.

Until I wrote Half a Life, I found math personally treacherous—its A-to-B-to-C arrogance, its Boolean surety: I operated the car. The car hit the girl. A=C. I killed the girl. Algebra makes no allowances. Or maybe it does—when it leaves the workbook and enters our flesh-and-blood world.

With this book I wrote what hurt; I looked it in the eye. And, for my readers, watching somebody work through those feelings has brought a kind of catharsis.

This is the story I would have needed to read when I was 18. I wrote it in part for the girl who died—to show how much she’s touched every part of my life—but I wrote it for that teenage me too, and for other people who feel guilt and don’t know if they should.

The lessons I learned are not glib, or very self-helpy. All the same, if one writes honestly and well about unwarranted guilt and how to overcome it, I think one can write a book that is self-helpful.

Darin Strauss