India, Jan. 8 -- While Siddharth Nigam as young Aamir Khan in Dhoom 3 (2013) grabbed audience's attention, the gymnast-turned-actor didn't do any other film, apart from a cameo in Munna Michael four years later. He says that he never wanted to "be a child actor in films". "Once people form an image of you as a child actor, it becomes difficult to play leading roles in movies when you grow up," he explains, adding that not many child actors have succeeded once older....