why it it so lucky?

its mystical power could be related to something as simple as the moon which changes its form (phase) every seven days.

In Japan this is a very fortunate number

Ancient Japan was founded around seven districts. In Japanese folklore, there are seven treasures and seven deities of good luck Japanese Buddhists believe people are reincarnated only seven times, and seven weeks of mourning are prescribed following death. The list goes on and on

Everything depends on your viewpoint and perspective, and your beliefs. If you believe that seven is the luckiest number out there, then for you it will be. If someone believes that five is WAY luckier than seven, then five WILL be luckier. Thinking something to be true, (unless someone lies), is the same as the truth. It's the same with so-called "unlucky" numbers and omens. If you believe the black cats and thirteen can only bring horrible events and situations, then bad things will happen to you whenever those two things come into your life. I personally believe that thirteen is a very lucky number (think lunar cycles, and the Druid woods to those of you who know), and that black cats are a sign of good luck (In Europe and Asia, black cats are sacred omens of good fortune). So if I spot a black cat or thirteen comes up somewhere, I am also less suseptible to bad luck following. I know it's a bit confusing, but it all depends on your preference. Sorry I got a little off topic, I digress. To sum it up, seven is so lucky because you and your sub-concious believe it to be. That's it; that's why. Thanks. *Tiger-lily Rain*

I don't really know but I found these interesting...

Seven is the number of spots on a common ladybug. Aren't ladybugs considered lucky too?

Seven Lucky Gods exist in Japanese mythology.

It is the neutral pH - the pH level of pure water.

The number of the Seven Virtues: Chastity, Moderation, Liberality, Charity, Meekness, Zeal, and Humility, corresponding to the seven deadly sins.

In the genealogy in the Gospel of Luke, Jesus is 77th in a direct line.

The number of heavens in Islamic tradition.

Why is thirteen so unlucky? Actually, in Italy 13 is the lucky number, so basically it depends on your culture, but then again who believes in supersitions like that anyways . . . oh wait . . . me! HAHA!

probably because its the number after satan's lucky number if u dont know what im talking about its 666

69 is my lucky number

i will have to watch this question and find out the reason my self.. i have alway found 3 to be lucky my self..

well if u turn 7 upside down it's L for lucky.(he he)

For some it may be but for me its 9

It could have started with the Bible, where on the seventh day God rested.