Lee Umbers talks to high-profile Kiwis about their biggest regrets – and how to live regret-free.
"Regrets, I've had a few," Frank Sinatra sang in My Way, the classic hit about looking back on life and defying its challenges.
But while Ol' Blue Eyes may have had "too few to mention", many of us have been remorseful over past misdeeds or lost opportunities.
Our biggest regrets centre around relationships, followed by working-life concerns, says the co-author of a study which surveyed a range of ages across the United States.
"We asked people their biggest regrets looking back over their life, and then our goal was to categorise these into different domains of life," says Dr Neal Roese, a professor of marketing at the Kellogg School of Management at Northwestern University in Illinois.
The most common regrets they found involved: romance (19.3 per cent), family (16.9 per cent), education (14 per cent), career (13.8 per cent), finance (9.9 per cent) and parenting (9 per cent).
Romantic regrets had two main themes.
There was "the one that got away".
"And relationships that went on too long or there was some big problem."
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Interpersonal regrets are so common because we are fundamentally social creatures, Roese says.
"We live longer if we have close friendships or close ties."
Award-winning Kiwi children's author Joy Cowley knows the pain of regret.
"I have lived… a very full life," says Cowley, 82, whose works have sold more than 40 million copies and who holds this country's highest royal award, the Order of New Zealand.
"There is only one thing that I would claim as a regret."
After her first marriage broke up five decades ago, "I was not coping well".
"To make matters worse I was getting a lot of unwanted attention from men who thought I was available.
"One of these … phoned daily and I found that oppressive, I didn't know how to deal with it.
"One evening I asked him not to phone again. He said he thought that I might have love for him. I said, 'Love you? I don't even like you!'.
"He said, 'That's not very kind', and put down the phone."
The following day the man was killed in an accident.
"I felt awful," Cowley says.
She still regrets her final words.
"I was as unkind as anybody could be".
Her comment was about her being "in a very low state" rather than his attentions.
At the time she was struggling, Cowley says - sharing care of her four young children with her ex-husband, working part-time and beginning her writing career.
"But that doesn't excuse what I [said]."
Shocked by the man's death and ruing her harsh remark, she determined to take "responsibility for the things I said" and be kinder with her words.
That included a commitment to compassion in the pages of the some 1100 children's books she would go on to write.
"While I don't preach to children - my most important thing is to entertain - kindness is very important."
"Regret is a good teacher."
Bronnie Ware, whose memoir The Top Five Regrets of the Dying has been translated into 31 languages, says her life was transformed by witnessing the laments of terminally ill patients.
The Australian was a palliative carer for eight years, tending people in their homes over their final 3-12 weeks.
She noticed more expressed regrets than didn't and the griefs had "repeated themes", centering around not having lived their lives true to themselves and their real wishes and desires.
Ware, 52, shared her insights in a blog post "Regrets of the Dying" which was read by eight million people.
She was invited to write her book, expanding on her post and including her personal journey.
A German production company is preparing to shoot a film in Australia based on the book and Ware's life.
The Australian author and motivational speaker says she gets constant feedback from people who after reading her memoir have launched new careers, simplified their lifestyles, sold their houses and gone travelling.
Regrets are often the result of not having the courage to be true to yourself, she says.
"But if you recognise the fact that you are on sacred time and that you are going to die, that gives you the courage."
Many of Ware's male patients lamented missing their children's youth because of having devoted so much time to their careers.
Sir Peter Leitch grew his Mad Butcher chain from one shop at Mangere East in 1971 into a 36-store nationwide business.
But his biggest regret: "I didn't spend enough time with my kids."
"I was trying to keep the business afloat," Leitch says.
"I was working long hours. Seven days a week half the time."
Leitch, 75, says he has been given a reminder of how precious the family bond is, as daughters Angela and Julie and wife Janice care for him as he recovers from multiple surgeries in April.
If he could go back in time, he would "make [more] time – simple as that" to spend with his girls.
League superstar-turned All Blacks sensation Sonny Bill Williams, 33, lives his life regret-free.
A pin-up prodigy with the Bulldogs a decade ago, Williams was the subject of criticism when he exited the NRL to join Toulon rugby union club.
But he went on to be part of two World Cup-winning All Blacks teams, and in a return season in league in 2013 won awards as the Roosters' player of the year and international player of the year.
Off the field, he has served as an ambassador for Unicef and is praised as a community role model. In March, he flew to Christchurch after the mosque shootings to comfort survivors and reach out with a message of hope and call for inclusiveness.
He is also a loving husband to wife Alana, and father of three.
"I have no regrets," Williams says.
"I do make countless mistakes and I'm constantly asking God for forgiveness.
"I believe that my mistakes have enabled me to become the man that I am today.
"Therefore, I have embraced my mistakes and do not view them as regrets - rather I view them as a part of the essential growth of who I am."
Health and fitness motivator Dave Letele, 39, was a successful businessman with a supermarket in New South Wales but after being financially overstretched he ended up back in New Zealand broke.
Depressed, the former national league representative's health fell apart and he soared to 210kg.
Encouraged into corporate boxing as the Brown Buttabean, however, he dropped 100kg along the way to a 20-fight professional career.
"I have made many mistakes in my life but I actually don't regret any," says Letele, who founded the Buttabean Motivation movement (BBM), helping thousands shed the kilos to gain health and hope.
"The reason is, because all those mistakes have helped me to relate to more people going through similar times.
"All the mistakes I made help me to lead thousands, because I have been knocked down and got up to prosper.
"I have made many, regret none, and work so others don't make the same ones."
One of the most common regrets of Ware's patients was they wished they had stayed in touch with their friends.
Christchurch-based internet and aerospace entrepreneur Mark Rocket was seed investor and start-up co-director of Rocket Lab in New Zealand, and is on the waiting list to fly on Sir Richard Branson's Virgin Galactic space tourism rocket.
"I had a good friend that helped me get my first business started many years ago," says Rocket, 48, who last year founded Kea Aerospace.
"He had a huge influence on my business skill development.
"As the years went by, we progressively headed in different directions and rarely saw each other.
"I found out that subsequently he went through a bad time and was struggling with some serious issues.
"I regret that he's no longer here for me to be able to help him."
Regrets over education tend to focus on lost chances, Roese says.
"People wishing they had stayed in school longer, completed further studies towards a more advanced degree, or studied harder so they had more opportunities."
While regrets can be painful, they can also be a call to action, says Roese, whose book, If Only, focuses on the experience of regret in daily life.
"Regrets are ... part of a background bit of thinking that is aimed at correcting a bad situation and moving us toward fulfilling a goal."
Roese says we can avoid regret by going out and doing things, "looking downward", and not overreacting.
Getting out and about opens up opportunities for fresh friendships and the chance of discovering "a new source of happiness".
If things don't work out, you'll rue it less than if you don't try, he says.
People tend to regret the things they did wrong about as often as the chances they didn't take.
But as they "look over larger parts of their lives, it's those regrets about things that they didn't do that tend to loom larger".
While regrets tend to be around situations that could have been better, "looking downward" is seeing how different decisions or outcomes could have made things worse.
"It tends to give [you] a sense of appreciation for those things that you do have."
And while negative events can feel overpowering at the time, people should not overreact.
"There is a tendency to look at things in the moment, and think of how huge and impactful they might be - we exaggerate the impact.
"It's worthwhile to remind ourselves that what seems like a big deal today, won't be such a big deal tomorrow."
Ware says we shouldn't judge ourselves too harshly over past mistakes because "part of being human is not being perfect".
The fact you can even look back and recognise that mistake means you have already learnt by it.
The top five regrets of the dying, as witnessed by Bronnie Ware:
1. I wish I'd had the courage to live a life true to myself, not the life others expected of me.
This was "by far the most common regret".
"People were astonished by how much power they had given to the opinions of others - friends or family or society."
2. I wish I hadn't worked so hard.
Men especially rued putting too much of themselves into their jobs – missing treasured family moments and not developing other areas of their life.
3. I wish I'd had the courage to express my feelings.
Many had kept their true feelings to themselves over the years to not upset others.
4. I wish I had stayed in touch with my friends.
"Dying people often want to have some laughter about good old memories [but] often the families are already in a state of grief.
"A lot of [patients wished] they had access to their old friends, so that they could have a little bit of light reminiscing."
5. I wish I had let myself be happier.
"When people were looking back, they realised they'd chosen to focus on dramas or problems or challenges, when [they could] have actually blessed themselves with more happiness."