At first, he was not interested in directing Dawn of the Planet of the Apes (2014), because the outline he was presented with did not have Caesar as the main character, who Reeves believed was the true hero of the franchise. When 20th Century Fox agreed to let him change the story to his liking, he agreed to direct it.
It's the idea that anticipation is as scary as anything in a movie could be. People's imagination is the most effective tool in creating terror or dread.