Oct.21 (GMM) Lewis Hamilton put on a brave face on Sunday after failing to secure the 2007 drivers' world championship in Brazil.

The rookie Briton, who could have clinched the title two weeks ago in China and with only a fifth place at Interlagos, finished seventh after a disastrous race filled with early errors and a temporarily faulty gearbox.

"I am still quite happy," the 22-year-old told BBC's Radio Five Live from Sao Paulo.

"To have come from GP2, who would have thought I'd be number two in my first season in formula one?"

Hamilton vowed to come back "even stronger" in 2008, even though Ferrari's Kimi Raikkonen will wear the number one.

He admitted that going off the circuit on the first lap was his mistake, despite being wheel to wheel at the time with his McLaren teammate Fernando Alonso.

"It was my mistake and I lost a couple of positions," said the Briton.

"I had the pace to get back but at turn four the car slammed into neutral and we don't know why yet.

"It was all against me in the end but I will go into next year and try to do a better job.

"It is 22 weeks until the next race and I am going to come back fitter, more relaxed, more experienced and I will have a better car," Hamilton added.