I do believe you can only truly know someone when you get the full picture
There isn't a single person in my life who has the "full picture" of my existence. It's something I've thought about before: my life is like a pie or a pizza or a pie graph. Everyone gets a slice. Some people get bigger slices, some people get overlapping slices, some people get just a little. But no one gets it all. I guess in that case no one truly knows me - by your definition - but I'm hard put to say if that is a bad thing.