Sheryl Sandberg made an emotional appeal for resilience and gratitude in her commencement speech to Berkeley's Class of 2016, where she spoke about her husband's death publicly for the first time.

Sandberg is the chief operating officer at Facebook and the author of "Lean In: Women, Work, and the Will to Lead." A little over a year ago, Sandberg's husband Dave Goldberg died suddenly of cardiac arrhythmia while they were on vacation in Mexico.

She said her own resilience after his death came from the "three P's," as identified by psychologist Martin Seligman: personalization, pervasiveness, and permanence.

Personalization, she said, "is the lesson that not everything that happens to us happens because of us." After her husband died, she blamed herself, and personally reviewed his medical records to see what critical symptom she had failed to notice.

"It wasn't until I learned about the three P's that I accepted that I could not have prevented his death," she said. "His doctors had not identified his coronary artery disease. I was an economics major; how could I have?"

— Sheryl Sandberg

Pervasiveness is "the belief that an event will affect all areas of your life." At the advice of a child psychologist, she and her two children returned to their normal lives ten days after Goldberg's death. She said she felt like there was no way to escape the "all-consuming sadness" of her loss.

"I remember sitting in my first Facebook meeting in a deep, deep haze. All I could think was, 'What is everyone talking about and how could this possibly matter?'" she said. "But then I got drawn into the discussion and for a second — a brief split second — I forgot about death."

"That brief second helped me see that there were other things in my life that were not awful," she continued.

Permanence is "the belief that the sorrow will last forever. For months, no matter what I did, it felt like the crushing grief would always be there," Sandberg said. But it wasn't true. Her rabbi encouraged her to "lean into the suck" of feeling bad — "good advice, but not really what I meant by 'lean in'," she joked. Accept your feelings, but know they won't last forever.

Working in some levity and knowing her audience of Berkeley grads, she quipped about the less-well-known fourth P: "Pizza from Cheese Board," a popular restaurant in town.

Toward the end of her speech, Sandberg talked about the times earlier in her life when she wished she'd known about the three P's: When she thought she'd get fired from her first job because she didn't know how to use the spreadsheet software on the first day. When boyfriends broke up with her and she blamed herself. When her first marriage ended in divorce.

I have a huge reservoir of sadness that is with me always — right here where I can touch it. I never knew I could cry so often — or so much. 

— Sheryl Sandberg

"The three P's are common emotional reactions to so many things that happen to us — in our careers, our personal lives, and our relationships. You're probably feeling one of them right now about something in your life. But if you can recognize you are falling into these traps, you can catch yourself. Just as our bodies have a physiological immune system, our brains have a psychological immune system — and there are steps you can take to help kick it into gear," she said.

The speech came to an end with a reminder to be grateful. She said she learned to truly appreciate her children, her friends, and her family after her husband's death. She compared it how her mother learned to appreciate walking without pain again after a hip replacement.

"I have a huge reservoir of sadness that is with me always — right here where I can touch it," she said. "I never knew I could cry so often — or so much. 

But I am also aware that I am walking without pain. For the first time, I am grateful for each breath in and out — grateful for the gift of life itself. I used to celebrate my birthday every five years and friends' birthdays sometimes. Now I celebrate always. I used to go to sleep worrying about all the things 

I messed up that day — and trust me, that list was often quite long. Now I try really hard to focus on each day's moments of joy."

Finally, she told the audience, appreciate your own capacity for resilience when you're sad or disappointed. Expand that resilience beyond yourself to the companies and communities you create.

— Sheryl Sandberg

"When the challenges come, I hope you remember that anchored deep within you is the ability to learn and grow. You are not born with a fixed amount of resilience. Like a muscle, you can build it up, draw on it when you need it. In that process you will figure out who you really are — and you just might become the very best version of yourself."