Growing up and especially being a teenager these days is extremely difficult and pressurizing. We are all different and unique but society is bunching us together into groups that we then use to get a false sense of identity from.
Let’s look at a teenage boy as an example and see how society and peer pressure can cause him to veer away from who he truly is to fit in with a bunch of people who are also just trying to fit in with others around them.
So, he arrives at school one day with a new haircut, one which is not currently in fashion. Some of his peers make a joke about it and laugh at him. He takes this very personally and is hurt by it. Sadness and fear of peer rejection arise which would be tough for a teenager to deal with. The next time he goes for a haircut he will inevitably suppress his natural unique desires and opt for a fashionable (the same as everyone else) haircut.
Now this might seem like a minor issue but what has just actually happened is that he suppressed his natural unique desires, authenticity and his true identity and is now making choices based on society. As this continues through the years, his true self is buried away to the point where it is difficult to access even if he tried to do so and society takes over. Society as I am referring to here comes in the form of mental conditioning; beliefs about what he sees everyone else wear, act like, do, how they behave and so on and this is what his morals and judgments get based upon. And so he continues his life making sure that he doesn't step outside societies expectations of him, completely unaware of how a few minor events in his teens have created the mental conditioning to make him who he now is (which is not his true self). It happens so subtly over time and most people don’t question society or their own belief structures nor are they aware of the thought patterns that influence their decisions.
Now with his beliefs and morals based on his mental conditioning/society, he could find himself judging someone else for something that doesn't fit in with his warped views of life and thinking to himself, ‘How Dare You Be Different’.