How superstitious are you?
Most cultures have superstitions. My humble little tribe in Soutn Sudan definitely has lots of that. You don't whistle at night, or look at yourself in the mirror, or many other stuff. An owl cooing on your roof top is a sign of evil to come, a bad omen.
I guess nothing beats the age old Friday 13th fear in the Western world. It is called paraskevidekatriaphobic (I will excuse you if you cannot pronounce it. I couldn't the first time myself!)
I found it hilarious. Read for yourselves, folks.