In my best Jack Nicholson voice: "The truth?! You can't handle the truth!"
If we don't always understand ourselves, or like ourselves, in what sense do we suppose that others should be obligated to do so?
My wife and I spent whole nights on the phone with each other when we first met, so I'm sure that we know more about each other than anyone else does.
On the other hand, I'm also sure there are things we don't know about each other. For example I am a pretty traditional guy who has barely dated more women than he's married, and who has definitely not had sex with more women than he's ended up marrying. Whereas my wife is a typical west coast girl who long since lost count of her boyfriends and paramours. I know for a fact that some of these assignations were ill-advised and she hasn't told me the half of it. And I see no purpose in her doing so. Frankly, I don't want that to color, for me, the person she has become.
Similarly there are some things that happened to me in Christian fundamentalism that I don't see any percentage in telling her all about. I know that while in the main she is a very non-judgmental person, there are things she IS judgmental about and I see it as perverse to test our relationship and connection with facts that are no longer representative of who I am.
I suppose that might be true. I have never been in a 'true' relationship.