Robert Kubica says that he is expecting to be more like a rookie rather than a Grand Prix winner and a contester of five Formula 1 seasons this year.
Although he has tested with Williams and driven its car throughout the 2018 campaign, Kubica says that F1 has changed too much in the last 10 years for him to apply his previous knowledge when he raced for BMW Sauber and Renault.
"In Australia, I am more like a rookie driver than one who has already done five seasons," Kubica told Autosport. "The reason is because 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."
However, Kubica says that the knowledge of how to compete against the best drivers in the world has stayed with him, and he believes it will be a benefit to his first F1 campaign in nine years.
"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."
Bahrain International Circuit - Winter testing