These questions, as earlier questions from you also do, teeter on a thin line between philosophical/academic and personal growth/therapeutic advice. But I believe you know that this forum is not the place to request or recieve the latter.
1) Yup one can get all tangled up in blue, if one fails to develop certain cognitive and psychosocial skills that have been written about by a zillion theorist from Freud to Piaget to Erikkson to McGoldrick and more.

2) There is a good bit of sociological research on self-disclosure. Interestingly, we do more of this with strangers and friends than people we are dating or engaged. That is sort of like saying, "I want my potential mate to NOT know the real me until after we are married!" But that's the research. See Olson & DeFrain, MARRIAGES AND FAMILIES (5th ed.), p. 112, for instance. The why is speculation.

3) I assume the keyboard I am using is not "in my mind" and I CAN know something of it. Why not others as well? So, I say, 'know thy self' and it will be easier to know where I end and the keyboard begins, no?