Her husband, David Goldberg, chief executive of SurveyMonkey, died in early May at age 47 in an accident.

Her 1,731-word post has gone viral, and was shared hundreds of thousands of times less than a day after it was put up.

Ms Sandberg wrote about how she had spent her past 30 days and the lessons she had learnt while mourning: "I have lived thirty years in these thirty days. I am thirty years sadder. I feel like I am thirty years wiser."

The lessons Ms Sandberg listed include gaining a "more profound understanding" of what it means to be a mother, and learning "some practical stuff that matters".

Here's what others had to say about death.

Steve Jobs: Live each day as if it's your last

At his Stanford University commencement speech in 2005, the late Steve Jobs, CEO and co-founder of Apple and Pixar, shared stories from his life urging the graduates to purse their dreams and see opportunities in life's setbacks - including death itself.

During his speech, he quipped, "If you live each day of your life as if it's your last, some day you will most certainly be right."

Randy Pausch: "Better than most of you"

The late Randy Pausch, a Carniegie Mellon Professor, gave an upbeat lecture titled The Last Lecture in 2007 to over 450 students, staff and friends.

Before the lecture, he told his story of having pancreatic cancer and that he only had three to six months to live.

But he declared that he was still in the best shape of his life, "better than most of you". He then did a series of push-ups on stage.

Dr Richard Teo: Wealth and glamour brought him "zero joy"

Singaporean Dr Richard Teo was a successful opthalmologist turned cosmetic surgeon who lost his life to lung cancer in 2012. Following his death, a 22-minute video of him sharing his thoughts with a dentistry class went viral.

He said his "world turned upside down" on the day he learnt about his illness, but he found comfort in his family and patients. He shared that his wealth and glamorous lifestyle brought him "zero comfort, zero joy, nothing at all."

He urged the students to never lose their moral compass and always put themselves in their patients' shoes.

Leonard Nimoy: Live long and prosper

The late Leonard Nimoy, who was best known for his role of a logical science officer Mr Spock in the sci-fi TV series Star Trek, died in January this year. Besides acting, he also wrote poetry, children's stories and was an active Twitter user. He often signed off his tweets with his signature line "live long and prosper."

The day before he was admitted to hospital, Nimoy posted a poetic tweet comparing life to a flowering garden and a poem about love.