No race in Jenson Button's 247-grand prix career will be as challenging for him as this Sunday's season opener in Melbourne's Albert Park. He made his Formula One debut there with Williams back in 2000, and now faces racing for the first time since the death on 12 January of his beloved father John, a hugely popular figure in the paddock.
"It's been a pretty strange couple of months," he says reflectively, as we sit in a quiet room at McLaren's Technology Centre, which elsewhere buzzes as the newly energised team prepares for the fight ahead. "I would say horrific, but in certain ways it's been nice, the messages of condolence, people's thoughts about my father, things I never even knew about him. So it's been very special in that way to see how many people he's touched."
He has coped, the way everyone has to in such sad circumstances, and having so much work to do testing the new McLaren MP4-29 in the past weeks has helped.
"When you're testing you get on with business, and you can have a laugh, you can have a joke. And somebody wrote me a nice message which said, 'Everyone else's lives will go back to normal but it won't for you. But never feel guilty about having a laugh or a smile because that's what he'd want.' That was a lovely message. But it's when you are away from racing or from people, that's when it hurts. It hits you like a stake through the heart."
He will be surrounded next weekend by trusted schoolfriends and family, including Jessica Michibata, to whom he recently became engaged, and says that will help.
"Obviously I won't be alone at the grand prix. But even with them all there, it's still going to be unbelievably difficult. Whether I liked it or not my dad was always the last person who gave me a high five or a cuddle before I got into the car. Even if I was trying to concentrate hard he would always be there and make sure he gave me that last hug. I'm going to miss that a lot.
"If I make the podium it would be unbelievably emotional, and if we have a crap race it'll also be emotional because he won't be there to pick me up. It was always those times when you had a bad race he would come in and put it into perspective, and that would annoy me in some way because I knew he was right and when your dad's trying to tell you something and you're in a bad mood, it's always difficult. So it's going to be a very emotional weekend, and not the only one this year."
Father and son used to have a quiet coffee together on race morning at the famed Stokehouse in St Kilda, but that is no more either. "It burned down," he chuckles. "Which I think was my Dad's doing! But I'll still have a quiet coffee at a pop-up cafe there."
Perhaps because of what he has been through, he seems stronger. Ready to confront the challenges, including another superfast team-mate in Danish rookie Kevin Magnussen. "For me it's different than for guys who have only been around for three or four years," Button says. "There is nothing I'm afraid of in F1. I'm going to go racing because I love it. And if I'm good enough this year I will be racing in F1 next year; if I don't do a good enough job I won't be racing. Whichever way it takes me, there's nothing that scares me. I'm so excited about getting out there and racing, and I have no fears and worries."
On his team-mate, he adds: "Kevin is going to be quick, but you'd expect that. If he's driving for McLaren he has to be quick. I trust his feedback and believe it, which is very important."
The new regulations turn the clock back to the era of Alain Prost versus Ayrton Senna, where F1 measured the full spectrum of a driver's talent and placed a premium on qualities such as self-control and intelligence. Button has both, in spades. "Intelligence will be important for all of us," he concedes. "For the mechanics, because these new cars are a lot more difficult to work on, and things just take forever because of all the electronic motors. Everything takes so much longer than normal.
"For the engineers, because the cars are very complicated and have so many different systems. Even slowing them down, it's complicated. And there are lots of things to play with, such as fuel-saving. The engineers are flat out.
"In a way our job as drivers is to understand what's happening and also to take some weight off their shoulders. I have certain systems that I can look at and use during the race so I know where I am for different things, so they can do a lot more with the strategy. Because at the moment they are flat out with everything else, let alone chucking in the strategy or racing the car on the circuit. But I think we have a good understanding of how to go racing with these cars."
He admits that, personal issues aside, he's excited about F1's new dawn. "From the driver's point of view, the cars are not as much fun to drive as they were six or seven years ago, but you learn to adapt and the important thing is that I'm still racing the best drivers in the world. And the regulations will make for fun races. The great thing for the fans is that no one's got a clue who will be quick this weekend."
He doubts Red Bull will be on the front row of the grid, and expects Williams to fight for victory. "People love that, and a real mixed-up grid and mixed-up result. And you'll have reliability issues. They loved it when cars broke down. It's going to be an exciting year for the fans and without them, we aren't going to be racing."