I suppose each person is unique in how much of their "true selves" they reveal to their friends, as well as in HOW they show this true self, and to what extent, to which friends. Some people seem to wear their thoughts and emotions on their sleeves, and some guard themselves in every response with some sort of agenda. But perhaps the act of guarding ourselves is as much a reflection of who we really are as is the open, honest communication between close friends.I certainly don't have any expertise in this field; those are just some thoughts.
I think you are right in this very simple question. The fact that we will never actually give our whole self to a friend is a very real concept. I know that even my best friends I have had over the years don't know every detail of who I am and even my overall potential. I am happy to share common ideas and facts of life with these friends, but I never opened up to anyone in my life quite like I have the past nine months with my fiancé Addi. The closeness you feel to someone comes from trust that they will forever support you and your ideas. I think my best friends of past have shared some ideas and thoughts with me, but I never felt that they would always support me and my ideas. I know now that the honest communication you share with a spouse, or in my case future spouse, is the only way a friend will ever have all of the real me in their hands.