This is the boring, short version- at age about 9 I decided to knit because I wanted to, so I learned from a helpful book that taught lefties.
This is the interesting version- At a young age I wanted to be like my sis and knit, but she was a righty and I was a lefty so she couldn't teach me. So, I found the book that my sis learned from, and it had a lefty section. The first time I learned, I knitted a TERRIBLE scarf and gave it to my grandma for Christmas. I don't know how happy she was with it
I put it down for a while, learned again, started again, stopped again, and then the same grandma gave me a bunch of yarn and needles for another Christmas and I've been into it since.
Tada, end of stories.