For some reason, the idea of watching something that makes you literally mess yourself is a compelling one. Unfortunately for you, there aren't many horror films out there that can devolve you to your six year old self, crying into your pillow at night over the monsters under your bed. Horror movies just really aren't all that scary any more. For all of the "advances" in the genre with found footage and gimmickry, the most universally scary things are the ones that have always been terrifying. A bump in the night; someone standing in the shadows and the irresistible fear of being attacked by anything when you're at your most vulnerable. This is why film-makers love getting scares in the bathroom, particularly when the characters are taking a bath or a shower. When you're naked and wet, you really are in your most vulnerable state; something that Hitchcock knew very well. He's far from the only one to centre his most provocative scenes in the smallest room in the house, either. So be careful when you're showering folks and philosophise over whether being clean is really worth risking your life for...
19. The Boogeyman (1980)
The idea of the Boogeyman has haunted children since the idea of scaring first appeared. There were literally cavemen babies worried about what was lurking in the darkest recess of their hole in the ground. Probably. In the 1980 film, the audience get to watch Jane as she attempts to take a shower but then becomes distracted by a pair of scissors. It is - naturally - only when she has stripped down to her undergarments that the Boogeyman commands her to kill herself by repeatedly stabbing herself.