The question "Is there anything I would do differently?" is the subject of 'The Top Five Regrets of Dying', an Australian palliative care nurse and singer has claimed.
Initially written as a blog, Bronnie Ware self-published the book at the end of last year.
By the beginning of this year, the sharply meaningful messages had ricocheted around the world and, by March, Hay House publishers had picked it up, released it internationally and had it translated into 25 languages.
It shares Ware's experience of being with people as they prepared to die.
"People grow a lot when they are faced with their own mortality," the Sydney Morning Herald quoted Ware as writing.
"I learnt never to underestimate someone's capacity for growth. Some changes were phenomenal. Each experienced a variety of emotions, as expected, denial, fear, anger, remorse, more denial and eventually acceptance.
"Every single patient found their peace before they departed though, every one of them," she said.
As she sat "around having a yarn" with her patients, she would ask about their regrets and whether they would do anything differently.
Despite vastly different stories and circumstances, common themes began to emerge. The book shares the most common five.
An aspiring musician, Ware spent eight years as a live-in palliative care nurse. Not having to pay rent gave her the financial freedom to pursue her musical ambitions on the side, part of the reason she took the job.
But, as she spent time with the people she was caring for, she became deeply affected by their insight. While not all her patients had regrets, it was the regrets that had the most profound impact on her personally. They give her the strength to make hard decisions when she needs to, she says.
"I know how profound it is to be [at the end] and regret and not be able to do anything about it," she said.
This knowledge drove driven her to become a mum for the first time at 45, release two albums and relocate back to the area she grew up in order to be close to her aging mother.
The message to live authentically and without regrets has also affected many of the books readers.
The top five regrets of the dying have also been listed in Ware's words.
The regrets start with "I wish I'd had the courage to live a life true to myself, not the life others expected of me", followed by "I wish I didn't work so hard".
"I wish I'd had the courage to express my feelings" and "I wish I had stayed in touch with my friends" follow next.
The last regret is "I wish that I had let myself be happier"