As soon as I get spooked I can feel my tempo slowly rising and before I know it I'm at full tilt. 

Oh good, glad it's not just me then. I was a little apprehensive posting that as I thought people might think I'm really paranoid or something! Without a doubt, it's much more comfortable when you are riding with at least one other person (not least from a safety point of view). The funny thing is I'm not a person who believes in ghosts or supernatural stuff, or thinks mass murderers lurk in the underbrush -but no matter what I try to tell myself and even when I attempt to think logically, I still get spooked now and again! For me at least, it shows how when it's just you alone in the dark, your mind really can play tricks on you.