Opinionating yourself into a corner

Are the strongly opinionated necessarily close-minded? I personally don't think that an open mind and an opinion are mutually exclusive, but last night my mother chided me for having 'too much of an opinion.' Part of this is a product of my mother's selective hearing, but I do wonder if there is a grain of truth to what my mother said.

One of my professors says it's nigh impossible to change someone's mind about politics after the age of 15. If an individual's worldview metastasizes in adolescence, are all subsequent opinions merely a result of path dependency? Certainly, your parents, community, and environment help establish your core values. I can't think of too many people who have made a 180 degree political turn post-college. And look at the peer pressure to stay within your stated party and views - friends, family, coworkers help reinforce your beliefs. I pride myself on reading the NYTimes and liberal op-ed writers, but I approach these articles with a bias to criticize. Hopefully, I'm approaching even my favorite like-minded authors with a critical eye, but I'm sure there is a subconscious approval process that undermines my ability to be truly discerning. So I agree that at least my core principles were established early on. My fundamental beliefs in the nature of man, the importance of freedom, and proper role of the state have not changed much in the last decade.

So how to keep an "open mind"? I think what my mother's concern primarily boils down to is a matter of tolerance and humility. Do I approach oppossing viewpoints with patience and a sincere desire to listen? And I shouldn't forget the possibility that I could be wrong. That's the best lesson I've learned so far in my adult life. It's ok to be wrong; not only becuase I often am, but also because it's a learning process. How you deal with being wrong is a better guage of the person you are than most else. So, yeah, I'm working on it!