LONDON, England - Lewis Hamilton's Formula 1 switch from McLaren to Mercedes in 2013 is an essential step that could be the making of him as a man, ex-McLaren driver David Coulthard believes.The Scot, who started his career at Williams and ended it with Red Bull, wrote in a London Daily Telegraph column that he felt the 2008 World champion had grown out of McLaren and had to make a move.MISTAKE TO LEAVE"Sometimes relationships just reach their natural conclusion," he said. "You don't live your whole life at home, even though the fridge is always full and the laundry gets done for you. At some stage you have to move out. Grow up. Become a man. This is that moment for Lewis."McLaren principal Martin Whitmarsh told reporters on Friday, when Hamilton's three-year deal was announced, that it was a mistake to leave a winning team.Hamilton, 27, has never driven for any other team. Even as a teenager he was backed in karting by McLaren (then co-owned by Mercedes) and had a sensational F1 debut in 2007. He's won three races so far in 2012 and 20 in his F1 career with McLaren.Coulthard saw the move as a sign of Hamilton wanting to take control of his own destiny after replacing his father Anthony as manager with XIX Entertainment and moving abroad, first to Switzerland and then to Monaco.SMALL SHAKE-UP"One by one he has moved out of the shadows cast by his father, Anthony, by (former McLaren team boss) Ron Dennis, and now Whitmarsh, the McLaren team principal," the Scot wrote. "It isn't all about winning. It is at least as much about the journey, about how you act and how you feel within yourself."Hamilton's move triggered a small shake-up in the paddock, with Mexican Sergio Perez signing a deal taking him from Sauber to McLaren as the Briton's replacement. German seven-times World champion Michael Schumacher, the most successful driver the sport has yet seen with 91 race wins, has had to move aside for Hamilton."So many questions are thrown up by Lewis's decision to join Mercedes and F1 is undoubtedly the better for it," Coulthard concluded. "With luck, Lewis will be as well. This could be the making of him as a man."