what's the 9?

I like them because they are graphic and....I have a thing for fonts, letters, numbers, stencils and handwriting. Turns out there are other reasons to like a number necklace.
Some explanations that people have given me:
# of kids, # in family, lucky #, special dates or years, wife #3!, and my favorite was from a sweet couple at the ICE show who ordered a #1 because she was his number one girl!
(I wear a big blue 9....married in September)