Back in 1984, Arnold Schwarzenegger was already a very recognizable actor. However, "actor" was seen as more a technicality of his job than his talent and capabilities. This outlook changed quite sharply when it was decided that instead of playing the hero of this time-travel-killer-robot-dark-future thing James Cameron had been working on, he would play the villain. That meant instead of just being strong and yelling a lot, he had to portray a killing machine.. which it turns out he's very damn good at.