Nate Saunders takes a drive around the track at Le Mans to see what Fernando Alonso can expect ahead of his triple crown attempt this weekend. (4:14)

LE MANS, France -- Jenson Button is a man invigorated by life away from Formula One.

After his debut in 2000, the Englishman completed 17 seasons in motorsport's premier category, which included in his crowning achievement: the 2009 world championship. That title and the move to McLaren which followed saw his best seasons in the sport as he claimed all but one of his 15 career victories in a four-season spell.

But the next four years were, at times, difficult to watch. His final F1 win, the 2012 Brazilian Grand Prix, remains the last for McLaren. Button stayed with the team until 2016 as it fell further and further down the pecking order and the closer he got to his retirement, the more obvious it became he didn't want to be there. He will openly admit now he stayed in the championship for too long.

A year and a half later, as he prepares for his maiden Le Mans 24 Hours with Russian outfit SMP Racing, his demeanour is completely different to the man of late 2015 and all of 2016.

When asked how he's found life away from the F1 paddock, he flashes a big grin and tells ESPN: "It's been awesome. I've definitely done my years in F1 and stepping away was great, it was a good time for me to do it. Realistically, if I'd had the choice, I would have left half-way through the year [2016].

"I'm much happier as a person now, life is great, and I'm racing things I've always wanted to race in."

It's not difficult to see why. In the days before arriving at Le Mans, he and girlfriend Brittany Ward announced their engagement. On the driving side he's dovetailing his World Endurance Championship duties -- he has signed with SMP up for the rest of its 'Super Season', which runs until next year's Le Mans 24 Hours, meaning he is guaranteed at least two attempts at the famous race -- by fulfilling a long-held ambition to race in Super GT in Japan.

Jenson Button has been racing for Honda in Japan's Super GT series. Clive Rose/Getty Images

His Super GT commitments meant he missed WEC's season-opener at Spa-Francorchamps -- won by former McLaren teammate Fernando Alonso and his No.8 Toyota team -- and came to the gruelling Le Mans week with limited time behind the wheel of the LMP1 cars which make up WEC's premier category.

"It's a shame I couldn't more testing, four hours around Magny-Cours doesn't really get you ready for Le Mans, but it was good to get used to the switches and things like that. I've learned everything about the car here, really."

Button's SMP Racing are most likely to be in a battle for the 'best of the rest' spots behind Toyota, assuming the Japanese manufacturer can make it to the end of the race.

The future of WEC remains uncertain -- on Friday, the series unveiled its next set of regulations for 2020 and beyond. The details remain vague but what is known is that the current LMP1 cars will not remain, with the series likely to moving towards hypercars in order to entice more big-name manufacturers. That imminent change meant the opportunity with SMP was too good for Button to turn down.

Jenson Button will contest the 2018 Le Mans 24 Hours with SMP Racing. James Moy Photography/Getty Images

"Le Mans is something I also wanted to do but I didn't want to wait until I was 40 to do it," adds Button, who is now 38. "Who knows what's going to happen in two years, you'll have manufacturers involved and have more of a hypercar base, is what they are saying.

"They won't be as quick as these cars so it's nice to get into these monsters to drive round in. Doing anything around here in under three minutes twenty [seconds] is just madness. So that's very exciting."

Asked how he has found the cars themselves, he said: "It's completely the opposite of what I thought. I thought I would have a lot of power and not a lot of grip in the high-speed, especially compared to the Super GT I'm used to in Japan. But it felt like it had very low power and very good grip in high-speed corners.

"I know it's not -- we're doing 338km/h on the straights, which is not slow, but the downforce the car produces here is very impressive here in high-speed corners."

Jenson Button is happy he had a chance to sample WEC's "monsters" before the series' next regulation change. JEAN-FRANCOIS MONIER/AFP/Getty Images

Part of Button's preparations for the race included his first runs at night at the legendary 13km Le Mans circuit during practice and qualifying this week.

"It's tough! I think a lot of people find it tough because there's a lot of people making mistakes. That's when I did my quali run, it's like 'OK, every three or four corners there's a car off the track', there's grass and everything being thrown on the track. It was a bit messy, so hopefully everyone's calmed down a bit and got used to it. It was my first time to be on track with other cars, so it was an experience.

"It's not comparable to anything I've really done before because some areas of the track are so dark -- eventually it becomes second nature at some parts of the track when you've done so many laps through the day."

The next challenge, sharing driving duties with two other teammates for 24 hours, might not seem like a huge challenge for a seasoned triathlete, but for Button it is comparable to nothing else in his career.

"I think my levels of fatigue are not an issue because I've done triathlons for years, four-and-a-half-hour races, pushing yourself a lot harder than you're pushing yourself here. Here it's more mental than physical, I think that's the bigger issue I'm not used to, reacting to things for that period of time.

"I don't know if you ever get used to it. It's not natural to be awake for 36 hours, whatever we are -- we're up at 7 in the morning and the race doesn't start until 3, so it's a much longer day than people think. The Le Mans 32 Hours, basically!"

The Le Mans 24 Hours starts at 3pm local time on Saturday, June 16.