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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Before traveling a person should, apparently, sit on their luggage. (Russian)
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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 some parts of England, rum is used to wash a baby's head for good luck.
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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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Two people breaking a wishbone is said to lead to good luck for the person with the larger piece.
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Collect seven or nine different flowers on midsummer eve and place them under your pillow and it is said that you will dream of your future spouse. (Sweden)
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