Williams Racing announced Kubica would join George Russell last year, solidifying his return to the sport after an eight-year hiatus as a result of his life-threatening rally crash in 2011.
The 33-year old won the 2008 Canadian Grand Prix and racked up 12 podiums in 76 race starts during the first stint of his F1 career.
Despite holding a development role Williams in 2018, as well as testing for Renault in ’17, Kubica has not raced in F1 since the 2010 season finale in Abu Dhabi.
“In Australia, I am more like a rookie driver than one who has already done five seasons,” Kubica told Motorsport.com.
“The reason is that F1 has changed so much. F1 has always been changing and if you compare the cars from the start of the 2000s to the end, they are completely different.
“I have to work hard and I’m looking forward to the challenge but also I’m looking forward to finding the natural way of driving that I had in the past – when you are in the car often, racing every 10 days or so.
“Everything should come as naturally as possible, you don’t have to look for it and it’s all natural.”
Kubica, who turned down a development role at Ferrari, will be partnered at Williams by Formula 2 champion George Russell next year and admits that his previous seasons to give him an edge when it comes to re-entering the pressures of Formula 1.
“What is helping me is that I lived this sport on such a high level, so I experienced what it means to be an F1 driver and what it means to race against the top drivers,” said Kubica.
“I hope that this experience will help me to achieve the levels which I would like to and this is the goal.
“My feet are on the ground and I know what is coming next is a big challenge from a sports point of view. Being in F1 among 20 F1 drivers is a big honour but also a tough job, so there is a big challenge in front of me.
“All I care about is my job and what I am doing, there will always be someone judging you and in different ways.”