Paranoia or Intelligence?

Ever since I joined, I've always been a bit worried about posting my "good" writing. I've uploaded a lot of my earlier, not-as-good work onto here. The things I take more pride in, like a novel I'm currently working on or my best poems, I've been nervous about uploading. Not just about people stealing it in general, but my ideas (story-wise). I feel that my ideas are at least a little original and not all that generic, so I don't want someone using my ideas and getting credit for them. It's not that I think I'm amazing or anything, I just don't want to lose what I've worked so hard for.

Comments? :? Am I being silly and overly cautious or smart?