Describe the superstitious symbolism of three's:three people being granted three wishes, three people in the White family, three knocks at the door.

In the 6th Century BCE, the Greek Pythagoreans believed that the number 3 represented Harmony since 1 meant Unity, and 2 meant Disorder. Add the two together and you reach a harmonious conclusion.

Explanation:

The number three is considered lucky for a number of reasons. First, there's the fact that a man and a woman - a unit of two - can become a unit of three with the creation of a child, giving the number three a bit of magic all around the world. In Christianity, there's the Father, Son and Holy Spirit; Islam has its three main holy sites. This magic associated with the number three has given rise to sayings like "third time lucky" and "third time's a charm," both of which suggest that two failures are sure to be followed by success on the third attempt.