Monte Carlo - It seems slightly odd to be talking about sacrifices when you are a multi-millionaire son of an even richer father while sitting close to your Monaco apartment on the hills above the aquamarine tints of the Mediterranean.
But this is how it is for Nico Rosberg, the Formula One world champion who walked out of his high-speed business just five days after realising his lifetime’s dream by taking the title against his oldest rival, team-mate and sometime friend Lewis Hamilton.
In his first major interview since he stunned the sporting public by going out at the top, forgoing his £18 million-a-year (R300 million) contract to stay on at Mercedes, he talks more candidly than he could when he was in the maelstrom of the biggest contest of his life - the battle he won at the Abu Dhabi Grand Prix in November 2016.
He paints a picture of a man who squeezed out every drop of his talent in a one-off attempt to do what he had never managed before in any series: beat his old karting pal over the course of a season.
By sacrifice, he raised himself to a level of intensity he could never hope to replicate.
One small example: "I stopped cycling in the summer to lose one kilo," he says. "The next race I was on pole at Suzuka by one hundredth of a second. One kilo is worth three hundredths per lap. So I was on pole thanks to losing my leg muscles. It got me the win. Those were the small details I went into."
Now he sits in his seat, with the Med over his left shoulder, and declares himself "very relaxed". He says: "Start wherever you want."
Well, let’s start at the end of his career, with that momentous decision to quit aged 31, an upheaval that some observers thought he should have mulled over to be certain his mind was settled. Others said he should defend his title.
"I can tell you this," he says. "My Formula One career book is closed with the most awesome ending I could have imagined. And I love books that end happily.
"I am turning my life upside down, so it will be full of challenges. The underlying belief, however, is that it felt totally right. I am following my heart.
"Now I am excited because of all the freedom I have. When I was racing I was in a hamster wheel, a good one, of course, and I am so thankful for everything it gave me. I wouldn’t do anything differently.
"But to be the best in your sport you have to make a lot of compromises.
"Now I look at my calendar for March and it’s totally white - blank from start to finish. I can decide to explore whatever I want to. It’s about spending more time with my family, which last year was a serious shortcoming.
"It’s learning to play the guitar. You need to be in one place for a while to be with your teacher and get into a rhythm. That’s a ridiculous, small example. There are bigger things, too: I have received so much in my life - the world championship, my family. I’m exploring what I want to do. Maybe something with kids, 10-year-olds, an age where I can make a difference."
His decision to retire had been percolating in his mind since that leg muscle-light Suzuka win, the one that put the title in his own hands. He spoke briefly to his wife, Vivian, about it before the final race. He says she would have supported him carrying on, but deep down favoured his coming home rather than risking his limbs further.
They spoke about it again on the night of his championship win. But it took all his courage to inform his team principal at Mercedes, Toto Wolff, calling him rather than sharing the news as they flew over from a sponsor event in the Far East. And when he told one of his closest friends, his mate replied: "Now I understand how my sister felt when Take That split."
It was a good line, but did not help settle his nerves for the call he was relishing least, to father Keke. Rosberg Senior is a friendly but no-nonsense Finn - world champion in 1982, when he would routinely step out of the car and light a cigarette.
He made multiple millions as a businessman post-career and guided young Nico into Formula One. He then stepped aside to give his son his own head soon after he had established himself at his first team, Williams, for whom he made his debut in 2006 with the fastest lap in Bahrain.
"I can see with my daughter now," says Nico, "that it is hard to let go. Wow, very hard. It was not easy because he had all the experience and wanted to give it to me and to protect me from the shark environment of F1. To stay in the background was massive."
So how to make the call to the man who had shown up for the first time in the paddock for ages, a few hours after Nico’s title win, smoking a giant cigar? The answer was instead to call his mother, Sina, a discreet, elegant German from whom Nico probably takes more of his non-racing traits.
"I talked to Dad in detail afterwards. We went deep, but he told me that he was happy if I was happy."
Keke and Sina’s marriage is one of motor racing’s closest and most enduring, and it is to that example of family life that Rosberg aspires more than anything. He met Vivian as a three-year-old playing in a sandpit at a Spanish seaside resort. They now run Vivi’s Creamery, an ice-cream parlour close to their Ibiza holiday villa.
Vivian still works as an interior designer, though she took the domestic strain with the night-time cries of their daughter, Alaia, now aged one-and-a-half.
"Vivian did absolutely everything," says Rosberg of his supportive saint for whom he hid gifts in their Monaco home to find when he was away. "If our daughter needed something, Vivian would be there. Never, ever, did I do a tough moment with my daughter. I was working on beating jet-lag by moving to the time zone - I was going in one-and-a-half-hour stages per day.
"It meant I could be asleep into the afternoon and living at night. It was horrible. And Alaia knew Daddy couldn’t be disturbed. She was so impregnated with the concept that whenever she came to the bedroom she had her finger over her mouth and said, 'sush'. Now I am doing those tough moments. It creates a bonding. She gives the love back to you. It’s amazing that she knows when you are suffering with her."
Diet was another sacrifice. Out went sugar - including ketchup. So much so that his hands shook for 10 days. He gave up drink except at the odd post-race party where, fuelled by vodka, he would be the last man standing, as likely as not belting out karaoke versions of Queen and Bon Jovi.
He spent hours working with his engineers at Mercedes’ factory in Brackley, his technical input valued as he was an A-grade student who turned down an engineering course at London’s Imperial College. Meditation came in - all to beat the force of nature called Hamilton.
"There was a good mind man up the road and I spoke to him," says Rosberg. "I read books on philosophy. You know if you woke this morning and felt bad, some genius, maybe 2000 years ago, had experienced the same and wrote about it.
"You can learn from this why you are feeling jealous or angry or stressed. And if you understand it, you can address it and deal with it.
"I would spend 20 minutes each morning and evening meditating. I don’t like that word, actually, it’s about concentration and awareness practice. I would sit down and just think of my thoughts, learning to relax my mind. After 20 times, your mind calms. When the fear crept in that I would lose the championship, you connect with the thought and have a discussion with it. Then the negative thought loses its strength."
While Hamilton was on a social media whirl, Rosberg spent five months off Facebook. Focus was his watchword.
The Hamilton-Rosberg relationship was unique. In their dark moments, their long-standing friendship may have helped. At other times, I suggested to him, it may have added extra friction - like two exes together.
"That’s right," he says. "The anger is bigger if that person you know so well does something that crosses the line. Lewis is very good at going to the edge without going outside the grey area, thanks to his skills in the car. He is smart, very, very smart. I found it harder to go wheel-to-wheel. For him, it comes naturally.
"For me it is more rational. I have to work at standing my ground. I got more aggressive because too often in the past he had walked all over me. I had to watch the videos and make improvements."
'Two world champions'
He knows he will have a pang as the new season gets nearer. Seeing his replacement, Valtteri Bottas, formerly of Williams, with his old engineers took some swallowing.
But he still meditates, he sticks to his diet and fitness, and spends three hours in the office working on new possibilities - which include maintaining a presence in F1, either working with Mercedes, where he is carrying on with some sponsorship duties to soothe the dislocation caused by his sudden departure, or as a driver manager.
He also wants to put on some muscle, something the jockey-like requirements of his old job precluded. His regimen is on hold, though, because he overdid it and is now suffering from tendinitis.
"I never wanted to emulate my Dad as such and thought that having done so I would draw a line under my career," says Rosberg.
"I am glad we can share in having accomplished the same feat. He is the only father to have been alive to see his son also become world champion and it makes me proud.
"At Christmas my mother had us round the table and said, 'I’m sitting here with two F1 world champions. How cool is that?'."