But Mark Webber, the author of the 'nutcase' jibe, said on Thursday that the Frenchman has turned it around.
"Yes," the Australian is quoted by the Russian website f1news.ru.
"But he had no other choice. This year he is coping with the problems better, but let's face it -- after last season, it (improving) wasn't too difficult.
"In Budapest he made a mistake in the situation with Jenson Button, but his overtaking of Felipe Massa was really good," added Webber.
So, with his Lotus teammate Kimi Raikkonen strongly linked with a move elsewhere, Grosjean is expected to stay at the team in 2014 -- perhaps as the new lead driver.
He agrees with Webber that he has been much improved this year.
"Well, a different state of mind, I think I've progressed a lot and worked on that and I think the 2013 starts prove that I did my duties," new father Grosjean said on Thursday.