How we perceive the world is completely different from one another. Every person uses their own senses to see the world; though two people might be in the exact same situation, they could be experiencing very different feelings towards the event. Nobody really knows exactly what or how another person feels about something. When a person tells another about something that happened in their life, though the latter thinks that s/he knows exactly how the former feels, it is only a mere assumption that s/he feels the same through their own experience. What they are not aware of is that the process of growing up is different for everyone so everyone would have different (more or less) beliefs and opinions on things, and thus the way they perceive the situation cannot be exactly the same, no matter how much they think they know how others feel. 

The difference in perception of the world also affects on people’s way of thinking, and what they dream about. Every person would have a unique objective in life, and even when they seem very similar, there are always some differences. Every person would also have their own ways to tackle and attain their goals, to achieve their dreams in a way that is ethically acceptable to them. Whatever they do makes sense to only them, and thus, they live alone in their own world among people who also live in theirs.

“We live as we dream - alone.” A very concise quote from Conrad’s book Heart of Darkness, explains this very well. No matter how hard Marlow (the protagonist) tries, he will never be able to get other people to see what he sees, and to feel what he feels in his trip because they have never been in his shoes, they have never experienced what he did. This quote describes perfectly the uniqueness of each and every person, and in all probability, every species on this planet.