That might subconsciously the reason why we don't share certain with anyone just like that - everyone knows us as fun people that often affect the mood of the group (of friends), and we know that if we were to be completely transparent we would bring the mood down. You explained your wish for your friend to be his silly self near you like he is with other people....it's because everyone likes and wants that from us, that we tend to choose very carefully when to share the deeper side of ourselves. Not everyone can deal with the fact that the charismatic, happy-go-lucky Ne-dominant is the same person with the deep Fi thoughts/considerations. It confuses people.
Is it that by its indefiniteness it shadows forth the heartless voids and immensities of the universe, and thus stabs us from behind with the thought of annihilation, when beholding the white depths of the milky way?