Sheryl Sandberg says the '3 P's' have helped her become a stronger person after her husband's tragic death

In a commencement speech at UC Berkeley on Saturday, May 14, Facebook COO Sheryl Sandberg shared some psychological insights that have helped her cope with her husband's death.

Dave Goldberg died suddenly on May 1, 2015, during a trip to Mexico. The commencement speech marked the first time Sandberg had spoken publicly about her experience.

Sandberg cited research by Martin Seligman, a professor at the University of Pennsylvania who is widely considered the founding father of the positive psychology movement. Seligman and colleagues proposed that our ability to deal with setbacks is largely determined by three P's: personalization, pervasiveness, and permanence.

Personalization refers to whether you attribute a negative event to internal or external factors - in other words, whether it's your fault.

Here's how Sandberg explained personalization: "This is the lesson that not everything that happens to us happens because of us" (emphasis ours).

Sandberg said that after Dave died unexpectedly from a cardiac arrhythmia, she blamed herself: "I pored over his medical records asking what I could have - or should have - done."

Once she read about personalization, however, she accepted that she couldn't have prevented his death: "His doctors had not identified his coronary artery disease. I was an economics major; how could I have?"

Pervasiveness refers to whether you see negative experiences as global or specific, or as Sandberg says, whether "an event will affect all areas of your life."

Sandberg said she went back to work at Facebook 10 days after Dave died - and for a split second during a meeting, she was able to forget her grief and get absorbed in the discussion. At that moment, she realized that her professional life could still be rewarding and worthwhile, even after tragedy had struck in her personal life.

Permanence explains whether you see an event as stable or unstable, or how long you think the negative feelings will last.

For months after Dave's death, Sandberg said, "no matter what I did, it felt like the crushing grief would always be there."

Gradually, Sandberg said she learned that "we should accept our feelings - but recognize that they will not last forever." In other words, you don't have to deny that you're feeling sad or hopeless - but you can also take heart that one day soon, you'll feel a little less sad and hopeless.

Seligman and his colleagues suggested that there are probably individual differences in how people approach negative experiences. Some might be more inclined than others to see those events as personal, permanent, and pervasive.

But as Sandberg's experience with the death of her husband demonstrates, it's entirely possible to change your style.

"Just as our bodies have a physiological immune system," she said, "our brains have a psychological immune system - and there are steps you can take to help kick it into gear."

Perhaps learning about and understanding the three P's is the first step you can take. Falling down after you've been pushed, and feeling like you can't get up, is only human. But it's also human to learn how to stand again, one foot at a time, so you're ready to face the next shove stronger.