The best of oneself

To state the obvious, my parents have known me all my years and though they do not know many aspects of my life and the personalities that accompany those lives, they know my temperament better than anybody. So sometimes I find myself thinking, "I can relax, I can be 100% myself with them without fear that they will leave me". And then I pause: "To be yourself" is often not the best thing to be. Surely it is better to be the best of yourself - what I try and be (though sometimes fail) with M and others? And then I think, surely I should be the best of myself around my parents too.