The superstitious symbolism of a black cat crossing one's path is dependent upon culture: some cultures consider this a sign of impending bad luck, while some cultures consider this a sign of impending good luck.
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Placing a hat on the bed is, apparently, bad luck. (South Carolina)
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Some motorcycle enthusiasts hang a biker's bell from a portion of their bike to protect themselves from evil road spirits.
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If one walks underneath an open ladder it is said to bring bad luck. Sometimes it is said that this can be undone by immediately walking backwards back underneath the ladder.
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It is bad luck to put new shoes on a bed (or a table) (comes from the tradition of dressing a corpse in new clothes and shoes and laying them out so everyone can give their respects) - (UK)
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Pirates believed that piercing the ears with such precious metals as silver and gold improved one's eyesight.
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In Asia, the digit 4 never appears in any Nokia handset model number, because 4 is considered unlucky in many parts of Southeast/East Asia.
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Opening an umbrella indoors is said to result in 21 days of bad luck. Some traditions hold that it is only bad luck if the umbrella is placed over the head of someone while indoors.
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