爲什麼西方人覺得13這個數字不吉利？

1. THERE WERE 13 PEOPLE AT THE LAST SUPPER.
“最後的晚餐”裏有13個人。

And tradition has held that the 13th to take their seat was either Judas or Jesus himself.
傳統的說法是：第13個落座的人不是猶大就是耶穌自己。

2. TRADITIONALLY, THERE WERE 13 STEPS TO THE GALLOWS.
依傳統，上絞刑架要走13步。

According to popular lore, there are 13 steps leading up to the gallows. Gallows actually varied wildly, but even then, the number was often brought up to 13.
根據流行的傳說，上絞刑架要走13步。實際上，絞刑架形式各異，但即便如此，也往往要湊出13這個數字。

3. WOMEN MENSTRUATE ROUGHLY 13 TIMES A YEAR.
女人一年大約來13次月經。

Some suggest that the association with 13 being unlucky is due to women generally having around 13 menstrual cycles a year (based on a cycle length of 28 days).
有人說13會和“不吉利”相關，是因爲女人一年大致會經歷13次月經週期（以每個月經週期爲28天計算）。

4. A WITCHES' COVEN HAS 13 MEMBERS.
女巫集會有13位成員。

Although a coven is now considered to be any group of witches (or vampires, in some tellings), it was once believed that a coven was made up of exactly 13 members.
儘管現在人們認爲任何一羣女巫（有的說法是吸血鬼）都可以組成集會，但大家從前相信集會一定是13位成員構成的。

5. 12 IS A PERFECT NUMBER, SO 13 MUST BE UNLUCKY.
12是個完美的數字，所以13一定是不吉利的。

In some schools of numerology, the number 12 is considered to be the representation of perfection and completion. It stands to reason, then, that trying to improve upon perfection by adding a digit is a very bad idea indeed—your greed will be rewarded with bad luck.
在一些數字命理學流派看來，數字12代表着完美和完整。然後，由此推理出，想通過增加一個數字來提高完美的程度其實是一個很糟的點子——你的貪婪最終帶來了壞運氣。

6. ZOROASTRIAN TRADITION PREDICTS CHAOS IN THE 13TH MILLENNIUM.
索羅亞斯德教預言在第13個千禧年會有大混亂。

The ancient Persians divided history into four chunks of 3000 years. And although the exact timeframes can vary, some scholars feel that at the beginning of the 13,000th year there will be chaos as evil mounts a great battle against good (although good will eventually triumph).
古波斯人將歷史分爲4大段，每段爲3000年。儘管準確的時間點會有所出入，但一些學者感覺1萬3000年初就會出現混亂，邪惡勢力崛起，與正義作對（儘管正義最終會取勝）。

7. 13 LETTERS IN A NAME MEANS THE PERSON IS CURSED.
名字由13個字母組成的人會受到詛咒。

There's an old superstition that says if you have 13 letters in your name, you're bound to be cursed. Silly, yes, but slightly more convincing when you consider that a number of notorious murderers' names (Charles Manson, Jack the Ripper, Jeffrey Dahmer, Theodore Bundy, and Albert De Salvo) all contain 13 letters.
有一種古老的迷信說法：如果你的名字裏有13個字母，你就會受到詛咒。聽起來很傻，但是想想那些臭名昭著的殺人犯的名字——Charles Manson、Jack the Ripper、Jeffrey Dahmer、Theodore Bundy和Albert De Salvo，這些名字裏都有13個字母，這種說法也就稍微有些可信了。

8. SUPERSTITION HAS MADE FRIDAY THE 13TH TOUGH FOR BUSINESSES.
迷信導致逢週五的13號生意難成。

Friday the 13th is an expensive day for businesses. One analyst claims that around a billion dollars a year are lost as people choose not to do business of any kind on Friday the 13th.
從商業角度來說，逢週五的13號是很昂貴的一天。一位分析人士稱，因爲人們選擇不在逢週五的13號做任何生意，每年大約損失10億美元。