A first name is an incredibly important part of someone's life. It is a characteristic that every culture has. It is, hopefully, a unique device for distinguishing yourself from the sea of people that inhabit this earth. The internet is riddled with baby-naming websites and articles. You are not born with a name engraved on your forehead.
So one question thrown around many times is how much does your first name affect your life? Since a name has nothing to do with genetics, it can be very decisively categorized into Nurture. Some people would argue that you are who you are no matter what the name ("What's in a name? That which we call a rose by any other name would smell as sweet"). Others would say that because you have that name, you have that life.
I personally believe that in most cases, your first name does not change your personality and life choices. If that was true, then all the Sarah's would be high school counselor and all the Katie's would be incredibly environmentally conscious. Do you see where I'm going with this?
There are some exceptions as to how your first name can affect your future:
Bad names and their outcome
I believe that if you have a ridiculous enough name, you either accept it to run your life or you overcome it. By overcome it, I when you curse your parents and "show them" by exceeding what the invisible standard is.
Still, it is interesting how much importance a name has, especially in your early years. I remember wanting to change my name to Nicole when I was in grade school. I remember not wanting to tell my middle name. Did those years change my life and personality in an irrevocable way? I don't think so, but maybe you think otherwise?