Happiness is the inherent nature of human beings 

Happiness is not a goal to be reached or acquired in the external world; rather, it is the inherent nature of human beings and a fundamental internal responsibility.

Happiness is a matter of internal chemistry; human experiences have a biological basis. The body is like a chemical soup. If you learn to organize your system so that this soup is naturally delightful and peaceful, joy becomes the inevitable result. This is a systematic method for managing your own inner state, independent of external circumstances.

Stop trying to squeeze happiness out of things or other people. Most people make their well-being dependent on relationships, money, success, or the behavior of others. Yet, since the external world will never unfold exactly according to your wishes, you inevitably become a slave to circumstances. True happiness arises exclusively from within. If you are already happy within yourself, you enter into a relationship to share your happiness, rather than demanding it from the other person.

Do not place your psychological reality above existence itself. The universe and nature function perfectly well. Often, however, a single, trivial thought is enough to ruin our entire day. We generally suffer not because of reality, but because of our excessive consumption of chaotic thoughts and emotions. When you realize that your mental constructs are not the absolute truth, suffering loses its power.

Let go of expectations and rigid conclusions. The primary cause of unhappiness is that life does not unfold the way we expect or have predefined in our minds. The more firmly we hold onto conclusions about ourselves and the world, the more rigid we become. Those who instead maintain flexibility and a playful lightness can approach any life situation with joy.