The 2009 F1 champion, who turns 44 on January 19, makes a full-time return to racing this year, joining forces with Jota in its #38 Porsche 963 alongside fellow Briton Phil Hanson and Denmark's Oliver Rasmussen.
Button, who will take part in all eight rounds of this year's WEC, which starts with Qatar on March 2, has opted to compete in a full season as he again wanted to test himself throughout a campaign rather than drive in one-off events.
Explaining the thinking behind his decision, speaking on the FIAWEC website, he said: “Well, I've been racing since F1 – I raced in Japan in Super GT, I was in WEC in 2018.
“I've tried loads of different things… the 24 Hours of Daytona, too, but you feel that you don't maximise what you can achieve with one-off races. And you don't get the best out of yourself doing it that way.
“So, I wanted to do a full season. You don't get a lot of practice pre-season and I wanted to do a whole season to see what we could achieve in WEC this year.”
Button was also happy to race for a privateer team in going up against the big boys of Hypercar, with BMW, Alpine, and Lamborghini joining the fray for the first time this year alongside Toyota, Porsche, Ferrari, and Cadillac.
In terms of what Button has experienced so far as he builds up to the campaign, that has left him amazed.
“But they're not as technically advanced as a Hypercar. An LMDh car has 38 pages explaining just what the steering wheel does! There are so many switches, you can adjust many different things for the same issue.
“There's a lot to learn from a drivers' point of view. Obviously, the driving is the same but there's so much more you can adjust within the car to help an issue that you have on track.
“It's staggering the amount of stuff and it blows your mind. That takes a while to get used to.”
Button at least will not be a stranger to the Porsche 963 as he drove the car in Petit Le Mans at Road Atlanta in October, finishing fifth with JDC-Miller MotorSports.
Again, the technical level of competence to drive such a car astounds Button, something he is now becoming accustomed to as he prepares to tackle the Hypercar class in WEC.
“I had one day of testing before the race and I got used to driving the car pretty quickly but it's all the tech stuff that takes a while to get used to,” he said.
“It feels like there are 20 switches for one thing, but they all do it slightly differently.
“These cars are very clever – they learn as you drive around as well. You can pinpoint certain corners of the data that you want something to change and it will change without touching anything – very clever but very complex.
“It takes a different type of driver. There's skill on track but you need to be an expert in engineering as well.”