I was introduced to it firstly by my father, whose side of the family has a rich and long history of magical practices and folkloreist beliefs. My best friend in elementary school at the time....her mother was a practicing Witch and said she saw something very powerful in me and gave me my first book on Wicca and Witchcraft.
My mom read tarot and did "witchcraft" all through out my childhood. My granny is Native American. My great-great grandmother wasa Swedish fortune teller- it just was in my blood. I was never forbidden to study or read about anything so I took to paganism like a duck to water. The only struggle I did have was trying to come out of the cliche broomclosest. I went to a friend's bible study and renounced Christianity that same night. My mother still considers herself ironically a staunch catholic. She thinks I"m Wiccan (which isn't quite right, but it gets the point across to the family), but she's ok with it. I've had a long complicated set of life experiences that would make a great movie, and all these just sort of solidified to me what I was.
I envy you, friend. I wish I had the accepting and experienced environment you had. I wish I had contact with my Native American relatives, but they were all pretty much banished from the family by my stiff-backed Christian grandparents for practicing Mysticism and their own religion. I would like to speak with you sometime :)