A single magpie is considered a sign of bad luck. A Guide to the Scientific Knowledge of Things Familiar recites an old proverb concerning the incidence of bad weather when magpies forage alone and a possible scientific explanation for this.
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Once a wedding ring has been placed on the finger, it is considered bad luck to remove it.
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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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If you catch a falling leaf on the first day of autumn you will not catch a cold all winter.
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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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Two people breaking a wishbone is said to lead to good luck for the person with the larger piece.
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When you speak of bad luck, it is said that one should always knock on wood. Also knocking when speaking of good luck apparently helps with having good luck. This is an old Celtic tradition related to belief of wood spirits.
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Placing keys on a table is considered unlucky. (Sweden)
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