If I am understanding exactly what cognitive dissonance is properly, I would have to say the most notable change that occurred in me was when I was twelve years old. At the time I was incredibly religious, my whole life revolved around my religion. At the same time however, I held a lot of socially left wing views (my support for legalizing gay marriage was the most important in this case). I had a few atheist friends at the time who would frequently talk to me about the topic of religion, and eventually one of them brought up the contradictions between my personal beliefs and what my religion would have me think. I had somehow never read the bible up to this point and was unaware of most of the specific things it said until I started debating with these new atheist friends. He showed me verses that went against everything I believed politically and I had to choose whether I would stick to my morals or my religion and I chose my morals.
I can easily say that changing your beliefs due to cognitive dissonance is a very good thing to do. It would be ridiculous to just cherry pick your beliefs and choose to ignore certain aspects of contradicting ideas so that you can live in your secure bubble. It’s important for your growth as a human to closely examine and scrutinize the things you believe and say, and make sure they match up properly, doing so might be uncomfortable at times and may force you to rethink the world but I believe that’s just an important part of life.