12 is the symbol of "completion" as in "the best days of your life are now done". See what happens when you turn 13? See the point?
Religions have considered 12 be something special for the same reason. 12 "Apostles", 12 signs of the Zodiac, 12 postulates of Marxism, and so on. Everything important has to come in twelves. Like a dozen eggs. And "Cheaper by the Dozen" in terms of the perfect family.
Except I wanted 14, and my wife wanted 16, and we got the difference.
Religions have considered 12 be something special for the same reason. 12 "Apostles", 12 signs of the Zodiac, 12 postulates of Marxism, and so on. Everything important has to come in twelves. Like a dozen eggs. And "Cheaper by the Dozen" in terms of the perfect family.
Except I wanted 14, and my wife wanted 16, and we got the difference.