I disagree with the notion that it's inherently a Bad Thing to "not be ourselves". I'm constantly making an effort not to be myself, because I'm wanting to be something better. "Myself" is, in no particular order, a lazy drone with minimal work ethic, a sex-starved male stereotype, a self-righteous pain in the butt, and an impulsive and easily distractable pleasure-seeker. I don't consider any of these things to be noble virtues, and it's my lifelong ambition to construct something better from those pieces of my "normal" self.
I also disagree that it's inherently right to live by the philosophy of "as long as it harms none, do what thou wilt". Everything we do has repercussions beyond ourselves. A married man downloading pornography will harm his relationship to his wife. A person who practices drug use may suffer from poor performance at work, affecting his company and coworkers. A parent who lives according to principles of greed and selfishness will pass those "values" on to his children, whether he says them out loud or not.
Am I going to go around imposing these beliefs on other people, harassing my coworkers with them or telling goth kiddies on the street that they're travelling the highway to Hell? No, of course not, because I know that's not a productive way to effect change in others. Instead, I try to live the life I think I should, and hope that the best parts of it rub off on those who know me. When invited to discuss my principles, I'll gladly do so. I may even bring it up with others, but I won't press the subject.
But I refuse to leave this world in exactly the same condition I found it. I fully intend to make a positive difference in those I meet, no matter how small. It's the least I'd expect of me.