I'm not writer but I did some L&c stuffs like videos, wallpapers and hum...some pics (some of you know what I'm talking about!). I've never told it to any of my friends and/or family. In fact, the only person who knows I'm on a L&C board is my sister. But she doesn't know about the "fanart" that I sometimes do. My best friend knows I'm a big fan of L&C but she doesn't know I'm a part of the fandom. Why didn't I tell her? I don't know. I really don't know because I wouldn't be ashamed. My parents know that I like "this superman tv show" but don't know how much I like it. They don't even know that my laptop is full of L&C files (episodes, fanfics, pics...).
I think they don't need to know. I'm not doing anything bad and I think it's great not to share everything. I have met great people online and I know they are really nice people who feel the same way than about being a part of a fandom.

Maybe I didn't say I'm in the fandom because I fear that people think I'm totally crazy (which I'm not :p ).