Why has a kids TV show about an eccentric man with a box that can travel anywhere in time and space become the BBC's longest running TV drama - and one of Britain's biggest brands?　　On its 50th anniversary, lifelong fan Matthew Sweet argues you ignore Doctor Who at your peril. It may be a piece of children's television, but he believes it's one of the most important cultural art..在这个世界上，没有什么是永恒的，除了爱。