i feel like this is a really pseudo-philosophical question with a really obvious answer and which doesn't actually ask anything ): like, i'm just gonna state the obvious and point out that you are you. there is no way that you could possibly be known better by yourself or anyone else. if you don't feel like you know yourself then either you've just known all there is to know for so long that you tend to ignore that fact (more likely), or there's just not much to know in the first place (less likely).
unless you have an actual identity disorder in which case that's fair enough