Dude, that shit's the worst. I get that constantly at my friends house, it always looks like someone is just passing the corner right as I look. I think his house is haunted though, so maybe it's not just me.
I always thought micro naps were when you fall asleep for like a minute at at time or something? I don't know, all I know is that I've never been able to lucid dream or anything like that. In fact, I usually can't even remember my dreams, and anytime I realize I'm dreaming I wake up. I also wake up if I die in my dreams.
Although I remember a dream I had a few days ago where I was riding in an elevator that went up/down thousands of floors in a few seconds, and I could literally feel the g-force in the dream. It's strange how our minds trick us into thinking something imaginary is real. Makes you wonder about reality...
*strikes deep, philosophical pose*