Sheryl Sandberg gave the commencement speech at Virginia Tech on Friday. She spoke about emotional resilience, drawing on the experience of losing her husband, Dave Goldberg, suddenly in 2015. Sandberg encouraged the graduating students to look for supportive communities that mutually nurture their members. She had to learn how to accept help, and change how she thought about it, after her family tragedy:

Before Dave died, I tried to bother people as little as possible -- and yes, "bothering people" is what I thought it was. But then my life changed and I needed my friends and family and colleagues more than I ever could have thought I would. My mom -- who along with my dad is here with me today just like yours are here with you -- stayed with me for the very first month, literally holding me as I cried myself to sleep. I had never felt weaker. But I learned that it takes strength to rely on others. There are times to lean in and there are times to lean on.

Sandberg also shared a new habit that she's found valuable:

My New Year's resolution last year was to write down three moments of joy before I went to bed each night. This very simple thing has changed my life. Because I realize I used to go to bed every night thinking about what I did wrong and what I was going to do wrong the next day. Now I go to sleep thinking of what went right. And when those moments of joy happen throughout the day, I notice them more because I know they'll make the notebook.

The themes in Sandberg's speech echo her latest book, Option B, co-authored with Wharton professor Adam Grant. Leigh Buchanan reviewed the book for the magazine last month, concluding, "Vulnerability has become a leadership buzzword. Option B is a book of radical vulnerability, in which a powerful executive describes herself facing hardship not with grim determination but with a quivering lip and tear-swollen eyes. The book may help sufferers heal. It may also help leaders lead."

You can read the full transcript of Sheryl Sandberg's commencement speech on Virginia Tech's website.