Well, I'm not sure I agree with that John. First off, why if a couple loves each other and click on that basic primal level, would they need to have mystery in their relationship? I know girls (and I guess guys) like that "bad boy" persona that has mystery to it, but thats someone you hit it up with in high school and college, not somebody that you marry.
Why? Because next thing you know their psychotic ass that was hiding their dark secrets starts beating you and cutting your body for their enjoyment. I'm not down with that crazy shit.
Secondly, if you really care for someone, I think you'd want them to care for you... knowing the entire you, and not basing that concept on some false front that you put up to entice them. If thats the case, the person doesn't really care for you, they care for the "actor" that you currently are, not whats deep inside.
Why get into a serious relationship at all if you can't share everything about yourself and be accepted for who you are? That just seems counter-productive to me.