Death is always a sad and profound experience, and those who are left behind are often filled with grief and mourning. They are always looking for the answer to the question, "Why? Why was the person I love taken away from me so suddenly and quickly?", and Facebok's Chief Operating Officer, Sheryl Sandberg, is no exception to this phenomena.

A month ago, Sheryl's husband, Dave Sandberg, died from injuries sustained while exercising. According to Sandberg's spokesman, the 47-year-old chief executive of online company SurveyMonkey fell off his treadmill at a private villa in Punta Mita, Mexico, and sustained serious head injuries. He was found by his brother, but died on the way to the hospital.

Dave's memorial service was attended by hundreds of Silicon Valley executives, such as Paypal co-founder Max Levchin, LinkedIn's CEO Jeff Weiner, and Hewlett-Packard's CEO Meg Whitman. U.S. President Barack Obama has also extended his sympathies for Sheryl and her family in a personal message on Facebook to the bereaved family.

Sheryl performed the shiva for the husband, which is a Jewish ritual mourning period for those who buries a loved one after they pass away. While most normal activities can be resumed after the shiva, those who have lost a spouse can perform the sheloshim, a 30-day mourning period.

Sheryl's 30-day mourning period has offered her both a time for reflection and healing, as well as a time to mourn her loss. In a post that Sheryl has written on Facebook, she writes, "I have lived thirty years in these thirty days. I am thirty years sadder. I feel like I am thirty years wiser."

However, Sheryl also writes that Dave's death has helped her gained a deeper understanding and appreciation of her life as a mother, and she vows to honor her late husband's memory by raising their children "as they deserve to be raised".