Knowledge: Chinese culture considers 13 as the number of gods which brings good luck while in Spain people avoid getting married on the 13th of any month and believe it is the number of devils.

Conversation:
My favorite number is 7
OK. Were you aware that the eastern Arabs made 7 into an uppercase V lookalike?
That's interesting. I like it because I also like the band avenged sevenfold
Avenged Sevenfold's current lineup includes Brooks Wackerman.
I wonder which number is considered evil!

Response: Well! Most Europeans avoid doing any ceremonies on the 13th and consider it to be an evil number.