The thing with cognitive dissonance is also a bit more subtle than just the duality of conflicting beliefs. It can often arise from unidentified conflicts that are outside of your conscious self awareness.
One that I am familiar with is religion. I knew a whole lot about the bible and christianity growing up. From an early age I halfway knew things like how, when I looked at road cuts through bedrock, those layers hinted at deep time and held a story that wasn't well alined with my beliefs. Then there was my love of dinosaurs as a kid and that too did not mesh with my religious narrative. Each little element of conflict was present on some subconscious like level, and my life became partitioned between this narrative belief system and evidence based reality. I had lots of peripheral consequences in life due to this building conflict, but I never allowed the core issue to come to a head in an attempt to rectify the disparity until I was around 30 years old.
Cognitive dissonance can also be dangerous and is a contributing factor in many crimes and heinous acts humans commit. Alternative expressions of individuality may also have an origin in cognitive dissonance. Identification of these underlying conflicts is reflective of a person's self awareness and can help one improve one's mental health by taking productive action to resolve inner conflicts after identification.