Do You Feel Lucky?

Recently while doing a trivia quiz I discovered black cats aren't a symbol of bad luck worldwide,in Europe and the US they were historically connected to witchcraft,and even in present times black cats in the US and the UK are less likely to be adopted. The opposite is true in Asian countries,particularly Japan where they are considered lucky.
You may have heard that in the US whistling before a performance is said to bring bad luck,but in most of Asia whistling at night is thought to attract ghosts or snakes. Russians believe that whistling indoors will bring poverty upon the house,so I guess whistling isn't always the cheerful thing it sounds like.
How about the 5,000 year old walking under ladders brings bad luck? Other than the obvious hazards involved with ladders here are a few more: In ancient Egypt walking under a ladder was unlucky as a ladder leaning against a wall created a triangle,a shape they considered sacred. In Christian beliefs it was unlucky because the three points of the shape represented the Holy Trinity. In Asia criminals used to be hung from the 7th rung of a leaning ladder. The funny thing to me about walking under ladders is they are usually in the way and walking around them could prove more hazardous that walking under them!