I know the feeling. I've always lived that way, as well. Part of it is that I spend my time divided between nerds and jocks, like I'm stuck in an 80s movie. I try to hide my jock side from my nerd friends and rarely reveal my nerdy side to my jock friends. It's not dishonest; it's simply not mixing interests to disinterested people.
Revealing the whole picture is not so easy when context often dictates the parts to be revealed. One thing that I'm finding refreshing about my fiancee is that I don't find it difficult to not wear a zillion masks. That is, I don't feel like any side of me is less interesting or more offensive than any other. It's a remarkably good feeling, frankly, and not something I've ever really felt with any significant other. That said, "the full picture" still may not be feasible, given that no one can crawl inside anyone else's head. A little faith is necessary.