SAO PAULO, Brazil - Lewis Hamilton was left feeling numb after failing to finish his final race for McLaren on Sunday despite starting on pole position and leading the race.The 2008 world champion, who is moving to Mercedes next season, retired after Force India's Nico Hulkenberg slid into him on the slippery Interlagos track as they were approaching back-markers while running first and second.LEAVING THE 'FAMILY'Jenson Button went on to win the title-deciding race for McLaren, the team's second win in a row after Hamilton's victory at the 2012 US GP.Hamilton told reporters: "I am happy for the team that we got a win and feeling good for the future. I feel numb, a little bit like I did in 2007, it is mixed emotions at the moment."Hamilton missed out on the title in 2007, his rookie season, by one point, also in in Brazil. "(It's) sad that we were leading and I didn't get to see through the race and also that I am leaving but I am excited for the future and hope I will have a little bit of luck at some stage."Hamilton has been part of the McLaren "family" since he was a 13-year-old in karts, with the team backing him through the junior series to F1 and Sunday was a farewell to the only F1 team he has known. From 110 GP's he has won 21 times with 49 podium places, 26 pole positions, 12 fastest laps and 913 World championship points.Button, who ended the season as he started it with a win, said he would have liked to have celebrated on the podium with his team mate one last time. "It's sad that Lewis isn't here to enjoy his last race with the team but it's racing and these things happen. I'd like to bid him farewell. We've had a good time together over the last three years."