Robert Kubica understands why many are doubting his ability to perform in F1, as he's been hearing the arguments ever since he embarked on his miraculous comeback.
After over a year of efforts, trials and tribulations, dashed hopes and testing, Kubica was handed a second lease on his life as a Grand Prix driver thanks to Williams for which the 34-year-old will compete in the 2019 F1 world championship.
In addition to the massive physical demands imposed upon him during his path back to the grid, the Pole has also been forced to contend with those who remain skeptical of his ambitions.
"If I would be a team principal I would also have doubts," admits Kubica.
"This year has been very useful because the first meeting, I remember, I said 'If you have any doubt, we shouldn't be doing it, because in difficult times it's easy to point the finger on my arm – I want to make sure that you are sure that I can do it'.
"First of all I have to be sure that I can do it, that's why I'm here, but second of all the team has to be convinced that I'm able to do a job."
Kubica's performance during testing with Williams obviously dissipated the doubts the Grove-based had. As for the others, the 2008 Canadian GP winner will work hard to win them over, telling them "to wait and you will see".
"If I think I will not be able to drive competitively fast I would not be here," said a confident Kubica.
"This is a normal way of thinking, that people see my limitations and they ask how it's possible that I do it.
"I know that it's hard to believe but Williams has seen it this year and I have seen it [for] the last 16 or 18 months, since I first tested an F1 car in Valencia that I can do it."