Okay. True story.
I was mountain biking with a friend late one afternoon in a relatively remote area of the nearby mountains. We rode a bit longer than we had planned and it was starting to get really dark. We got to the paved road heading back to the car when I noticed my tire was flat. Riding uphill with a flat was no fun at all, so I started walking. I told my friend to ride ahead to get the car and to come back to pick me up.
Within a few minutes, it was totally dark. Not your regular dark, either. I'm talking no moon, no stars, no lights, can't see your hand in front of your face dark. It didn't bother me, 'cause I'm generally not afraid of the dark.
Then I heard a noise. Thought it was a rodent or something in the bushes. Didn't pay much attention to it until I heard it again. Closer. Something was rustling the bushes. Thinking it was an animal of some kind, I cleared my throat and made some noises to scare it off. It rustled again. Same place. Sounded to be just off the side of the road ahead of me. No friendly animal stays around after the noise making thing, so I was starting to get nervous.
I looked around for a weapon, but the closest thing to something deadly I could find was my portable pump (tire was blown or it would have been useful). I grabbed the plastic, lightweight, useless pump and stood there for a few minutes. Didn't hear anything. I walked forward some more and heard the rustling again. I was scared as hell by now. I'm thinking it's a cougar. A damn loud cougar. Or a crazy guy. Damn crazy guys are always sneaking around in the dark killing people.
Thinking that walking/running is better than standing still, I start running with my bike, being sure to keep my bike between me and whatever is on the side of the road. A few feet ahead of me, in the darkness, I saw it. Just off the side of the road. Waiting for me. It was a plastic bag. Stuck on a bush. The wind would make it rustle just like a cougar.