Scared of the dark

I am petrified of the dark.  Always have been since I was a little girl.  But I don't really know why - there wasn't any particular event in my life that should have resulted in such a fear and yet I still need a night light.

Why is it that walking through an area at night can be so different to walking through in the daytime.  Light reveals all hidden corners, shows us what exactly is there and is somewhat comforting even when we don't know where we are or who anyone is.  Darkness brings out the shadows, cloaks the known making it unknown, forcing our senses to become super-heightened, making us jump at shadows, the slightest noise, the tiniest motion and god forbid when someone actually walks out of the shadows.

Fear begins to fill your senses, your ears prick at every noise, your eyes dart from place to place and you become convinced that those noises behind you are faint footsteps.  How can you trust anyone under the mantle of darkness?  Who knows what mischief is lurking?  What darkness beats in the hearts of those prowling the streets?  How can they be trusted?  The fairy tales of witches, demons, werewolves and vampires begin to creep out of my imagination - every horror story I ever read, every urban myth and every tiny snippet of horror movie I've ever seen all morph into a massive ball of fear.  Someone is there, they are going to get me and I have to run but I can't run because if I run they will catch me and my breath starts coming quicker and then there it is - the bus stop, the light, the people, the bus.  Safety. 

It is completely irrational.  There is nothing in the darkness.......