Twelve is so common in our western world B.M. (before metric) that I start to wonder if perhaps humans were meant to be polydactyls and somehow it never happened. I know that humans normally have 12 pairs of ribs. Maybe that’s it….

Twelve inches to a foot.

Twelve days of Christmas, from Christmas to Epiphany. Twelve drummers drumming, (etc.) Oh, please, don’t get me started.

Twelve to a dozen. A dozen dozen is a gross. Sounds about right.

Then the twelve tribes of Israel (from the 12 sons of Jacob). And 12 cranial nerves.

12 months in a year.

12 apostles.

In ancient Greek tradition, there were twelve principal gods of Olympus. Twelve labors of Hercules.

The chief Norse god, Odin, had 12 sons.

Twelve buttons on the telephone keypad! (Thanks to Dan Gent).

Twelve function keys on your computer keyboard.

12 signs of the zodiac.

The minute hand of an analog clock face moves 12 times as fast as the hour hand.

The Dirty Dozen, Cheaper by the Dozen, 12 Angry Men. Twelve people sit in the jury box.

“Twelfth Night” by William Shakespeare

In music, 12 major keys, 12 minor keys (using the tempered scale).

12 pence in a shilling.

Twelve is the last of the monosyllabic numbers.

Twelve men have walked on the Earth's moon.

I've always been fascinated by the number twelve and its multiples. Guess I'm in good company.