From the HitchHiker's Guide to the Galaxy.
"The Ravenous Bugblatter Beast of Traal is a creature that hails from the planet of Traal, and will eat anything. If you are to encounter one, the Guide tells you that it's impossible to slay, so you should wrap a towel around your head. This creature is so mind-bogglingly stupid that it assumes that if you can't see it, then it can't see you."
I felt like one while on a road-trip to Visakhapatnam and surely you'll feel like one on Indian roads. We were going at high speed and suddenly we see someone crossing the highway. We honked hard and the person simply looked down. So the idea is that, if he can't see you, then you don't exist. Or maybe they were using the SEP field technology.
In the following video watch the first person crossing the road and next a cyclist goes in the wrong direction as we wiz past at 120kmph (75 miles/hour).