After the abortive start to his career at scandal-ridden Renault in 2009, the Frenchman got a second chance at the pinnacle of motor racing this year, with Lotus.
By mid-season, he had proved his speed with three podiums, but the 26-year-old also became the subject of intense criticism for repeat mistakes, culminating in his ultra-rare race ban following the Spa-Francorchamps start crash.
After a period of speculation about his seat, Grosjean has been signed for a second consecutive full season in 2013.
"I had figured F1 was hard, but not that much," he admitted to Sport24.
"Gradually I realised that the difficulty of the challenge was at least a multiple of two compared to what I knew at the beginning.
"For sure I have been criticised a lot, but if you had told me at the start that I would finish eighth with three podiums, I would have signed for it immediately.
"Yes, I made rookie mistakes for wanting to do things too quickly -- for example, I wanted to get their (Lotus') first win at all costs.
"I hope I've learned now and grown up although there is still work to do," added Grosjean.
"I expect a different pressure now; I cannot commit the same mistakes over and I'll try to score points as often as possible.
"I hope to demonstrate the same pace as this year but be more consistent.
"In terms of the standings, I would rather not set any targets -- that would be another mistake," he concluded.