Excellent question that I was thinking of posting myself actually
I'm somewhat crafty and have been since I was a kid. I've always wanted to knit, but thought it would be someday later. Well that someday turned out to be the beginning of January of this year. So, first off, it was always there in me, just waiting for the right time I guess.
My mom started knitting in October last year, on her birthday, and it is a wonderful hobby that has really transformed her. We're long distance, so I would call her every weekend, and she always talked about knitting. Thing was, that she would tell me about a knitting technique and I wouldn't get it, but I would feign comprehension.
Really, I do it because I've always wanted to, but I do it for my mom as well. It's something we have in common and I LOVE it so much.
I also have a good friend who has been knitting for 10 years and that brought on the urge as well. Coincidentally, I was just at her place tonight and the theme was KNITTING STUFF. I saw her stash (OMG - MEGA bins) of yarn, needles, books and finished projects. We talked about knitting LYS's and anything related to knitting. It was a wonderful experience. I was all over her like a preggy woman indulging on a craving.
I guess it was a combination of things that finally led me to the yarn aisle at Walmart. Timing, a desire to enrich myself with a new hobby, my mom, my friend, and my husband's support.
I can't wait to hear about other knitters' beginnings. Bring em on!!