When you start thinking, you start doing. Or so one route of conventional thinking goes. When you take the time to plan out how you should appear, you're more likely to appear that way - plan before you say something, do something, try to be something. Even "fake it 'till you make it."
Joshua Glenn wrote this article on fake authenticity that describes the phenomenon of people trying too hard to "be something" and how this actually makes it less likely for them to make it.
Whenever "authenticity" is evoked, we are actually in the world of fake authenticity. Although Italians do open restaurants, there is no such thing as an authentic Italian restaurant. Although history, nature, race, and class are very real and very much with us, there is no such thing as an authentic past, an authentic outdoors, nor an authentic non-white/middle-class style of life... "Authenticity" is a reality-label from the art world, and as such it cannot be fixed to anything living and vital.
This describes the wannabe phenomena: as soon as a field or a group becomes defined enough to be recognizable by people outside that group, wannabe members of that field appear. I need to do this to act like a hacker. I need to wear these clothes to be in the "cool group" in high school. Mathematicians have these habits, so I'll pick them up. Engineers are geeky, so I'll make jokes about bathtubs and hysteresis. Sometimes these are reflections of who you really are and who you actually want to be. Sometimes you just want to look like you belong - have the benefits of being in a group without really "being in it." To be genuinely something takes a lot of work - work to the point where it becomes unconscious.
I'm particularly struggling with this because I'm fascinated by the world of advertising and branding - the craft and presentation of an identity, a psychology. I know I'm using green for some logo because it has positive "earth-friendly" and "growth" connotations. I use certain words, type in certain fonts, etc. because I'm trying to convey professionalism, down-to-earth-ness, seriousness, carefree-ness... project an image. Discovering who you are is good, and being able to be and convey who you are is great - but if you pay too much attention to the discovering and conveying, you might end up not actually having time to be. The advertising is great, but it's touting a product that was never developed. Or was developed in a completely different direction. Then it becomes false and you start trying to fool people.
Try too hard to be smart, caring, real... and you have less time to learn, to care, and to be yourself. Sometimes we need to just stop worrying about who we are and just be who we are, and trust that that will be conveyed somehow.