We are the sum of our experiences. Some people learn from them, some don't. Some just live within their own perspective and do not comprehend anything else. It's what we call narrow-mindedness. Narrow-mindedness is mostly created by one’s own fear, fear not being able to cope with what one could learn.
They don't realize to what they're missing. They stagnate, they don't evolve. Since everything around evolves, stagnation is as good as going backwards.
The hardest thing for people is admitting being wrong. Everyone is wrong once in a while, admitting it is no defeat, it takes a strong person to admit. Admitting adds to the learning process, which is a never-ending story.
Learning is a wonderful thing, it enriches us, it makes us more human, and it makes us feel good.