Here's my story:
It's 1992, and I'm in Junior High, and I've got a friend who is interested in D&D, and he think's I'd be someone to game with. I know Console RPG's well enough (being a big fan of Final Fantasy, Dragon Warrior, even the NES version of Pool of Radiance) and had heard the name Dungeons and Dragons and seen the old cartoon when I was little (besides knowing the NES D&D game back and forth). He loans me a few books to raise my interest, and I read them voraciously. My dad walks into my room and sees all this, and throws a royal fit, telling me that's satanic, it's devil worship materals, reading that will drive me to suicide and murder, and where did I get this. It was all returned to my friend (and I was discouraged by him from seeing him anymore). My dad "knew" all this because he'd heard a sermon in church years before about the evils of D&D and the "facts" that it was just a thinly veiled cult recruiting scheme and was this quick route to madness and satanism.
I still wanted to play D&D, and my mom honestly didn't care, so I'd bought a handful of D&D books and kept them well hidden in my room, but I was never able to find anybody to game with. In later years I discovered the Star Wars RPG and bought books for it ravenously, in full view of my dad. He asked "what ya got there son?" and I would just answer "Star wars books" and it would be the end of it. Sailed right under the radar. I finally found players, and began my actual gaming career with the d6 Star Wars RPG.
In later years, my dad still never knew I gamed for many years, until he visited my apartment and saw the bookcase full of D&D books (which he didn't comment to me at all, and made just a passing disapproving comment to my mom later, which she shrugged off and told him if I was going to join a cult or commit suicide I would have years ago, since I'd been playing for about 7 years at that point).
My mom thinks it's just a little weird, but it's no worse than a poker night with friends, and she admits she really doesn't understand it but it's apparently harmless.
The fantasy LARPing I do sometimes really confuses her, and she thought it was pretty immature, until I explained that it's a combination of camping, rennaissance fairs, and paintball games, and she at least kinda understood it at that point. As far as my dad knows, I just go camping with friends for a weekend a few times a year.