Myths/urban legends/superstitions that might influence people from France

These days french people takes much importance to the appearance of people, it seems to be that the fashion had influenced them all, they look to others and likes to be looked at, it's a good point since the restaurants and all recreation places are the most of times clean and well decorated.

They like the fashion and the good cuisine. Most of the times french people are very courteous and they are direct too, they are accustomed to say the things like they are, direct to the point, if you sometime get annoyed by this, you will later realize that french people are friendly and polite if you get more in touch with them.

But there are somethings in which they believe or superstitions that people in this country have.

• In France, it is believed that if you find one white hair on a black cat, Lady Luck will smile upon you.
  
• French peasants thought that black cats could find buried treasure, if they followed a specific ritual: find an intersection where 5 roads connected, then turn the cat loose and follow him.
• The French believed that if a girl tread on a cat's tail, she would not find a husband before a year is out.
• Singing makes for stormy weather.
• Knives are not to be givern as gifts.