Because everyone has different experiences, needs, and expectations, no one will see the world just as you do. I remember figuring this out when I was a young teenager, trying to help my mom understand how she was hurting me. When I confronted her, I chose my words carefully, I did not let emotion overwhelm my words, and I focused just on my feelings and not on attacking her character. I was as articulate and concise as I could be at that age. I remember being proud of myself with how well I expressed my experiences, and then noticing that there was no new understanding in her eyes. Nothing I said had stuck. I knew she loved me and would move mountains if she thought it would benefit my quality of life, but she could not hear me when I tried to teach her how to help me. That was when I realized that there was no magic word or phrase that would unlock the mental wall/barriers she had that kept her from understanding my perspective. You cannot make someone think or feel what you want them to think or feel.
In university I learned that each of us have "cognitive schemas," or rigid beliefs, that filter all information we take in from the world. We have schemas for nearly everything, from the social meaning of different colours to what makes a chair a chair, to more complex concepts, such as the meaning of love and pain, or the roles and expectations for different people (e.g., children, parents, police officers, etc.). Schemas are deeply ingrained, and they automatically affect behaviour and emotions, constantly shaping how we see and interact with the world. But since we each have had experiences unique to us, our schemas develop differently. So, two people can be looking at the same world and see very different things, sometimes making it difficult for them to understand each other.