Let us imagine the individual reality as separate systems. One system is external reality, the other is consciousness. The mediator between the two is the brain. When the brain is filled with good thoughts, memories and ideas, consciousness will interpret reality as something extremely good and giving happiness. And when we are negatively charged – with negative thoughts and negative memories, what we see around us will perceive it as dark, gloomy, depressing. One reality – different viewpoints and approach (different interpretations).
The way we interpret reality is critically important to us. Depending on how your way differs from the “average”, you can be defined in varying degrees – from “normal” to “strange” to “crazy”. Notice here the term “crazy” is related to the difference with others. There is no need to give examples of how the greatest people are considered as crazy.
The way we see the reality around us also works on how to feel. It is enough, for example, that the weather is gloomy and that it causes depression in some people. It is enough to have suffered an accident and become depressed. Depression is an adversary to happiness. There are many things that can influence how we look at the life around us.