Doctors later told me that I’d suffered an episode of sudden cardiac arrest. Almost 90 percent of people who experience such episodes don’t survive, and the few who do are typically left with significant impairments. And for three days after the event, my family tells me, I spoke gibberish. But on day four, I was discharged from the hospital with a clear head. Two weeks later, I was playing tennis with Tom again.

If that ambulance hadn’t happened to have been nearby, I would be dead.

Not all random events lead to favorable outcomes, of course. Mike Edwards is no longer alive because chance frowned on him. Edwards, formerly a cellist in the British pop band the Electric Light Orchestra, was driving on a rural road in England in 2010 when a 1,300-pound bale of hay rolled down a steep hillside and landed on his van, crushing him. By all accounts, he was a decent, peaceful man. That a bale of hay snuffed out his life was bad luck, pure and simple.

Most people will concede that I’m fortunate to have survived and that Edwards was unfortunate to have perished. But in other arenas, randomness can play out in subtler ways, causing us to resist explanations that involve luck. In particular, many of us seem uncomfortable with the possibility that personal success might depend to any significant extent on chance. As E. B. White once wrote, “Luck is not something you can mention in the presence of self-made men.”

My having cheated death does not make me an authority on luck. But it has motivated me to learn much more about the subject than I otherwise would have. In the process, I have discovered that chance plays a far larger role in life outcomes than most people realize. And yet, the luckiest among us appear especially unlikely to appreciate our good fortune. According to the Pew Research Center, people in higher income brackets are much more likely than those with lower incomes to say that individuals get rich primarily because they work hard. Other surveys bear this out: Wealthy people overwhelmingly attribute their own success to hard work rather than to factors like luck or being in the right place at the right time.

That’s troubling, because a growing body of evidence suggests that seeing ourselves as self-made—rather than as talented, hardworking, and lucky—leads us to be less generous and public-spirited. It may even make the lucky less likely to support the conditions (such as high-quality public infrastructure and education) that made their own success possible.

Happily, though, when people are prompted to reflect on their good fortune, they become much more willing to contribute to the common good.

Psychologists use the term hindsight bias to describe our tendency to think, after the fact, that an event was predictable even when it wasn’t. This bias operates with particular force for unusually successful outcomes.