There are worse things in this world than the monsters under your bed. The psychological horror that burrows deep into your skull, laying its eggs, is what brings terror to the modern reader. Drawing the larvae into the light for examination, that is how I think of the process of writing. It is an extraction of what I fear most, then I pass it on to my readers to inspect.
It is within the mind that true terror lives and breeds, not in closets or abandoned buildings. This is why modern horror tends to surpass the visceral and bore straight into the gray matter. I want to give my readers stories that stay with them. You are what you eat, after all.