This is a great article about why creative people are often also eccentric.
I am self-absorbed, and I couldn't help but think about my parents when I read this, and how my genes might affect my life. My mom is noticeably lacking in inhibitions of any sort, and my dad is intensely creative. I definitely feel like a round peg in a square hole much of the time. The main point of the article is that there are inhibitions in your brain that keep you from considering outlandish ideas, but if you are lacking these inhibitions, you tend to be eccentric. If you are lacking these inhibitions, and you are also intelligent, you tend to be creative. Lacking these inhibitions can also make you schizophrenic.
"cognitive disinhibition may be affected by genetic variations and ... it may be one factor that predisposes an individual to both creative thought and eccentricity."
So, there you have it.