Real happiness is eternal
What is real and what is unreal is one of the gravest doubts in our mind. Unless this doubt gets clarified, we shall never be able to achieve real happiness in life. Because real happiness is eternal happiness and unreal happiness is temporary happiness. Real happiness can never be achieved if it is dependent or associated with something unreal.
This world is considered to be unreal and the aatma (the pure divine self) is considered to be real.
Essentially, unreal is anything that undergoes changes, modifications, is impermanent and short lived. Anything which has a life span and which is born or created, and which gets destroyed over a period of time is unreal. There is nothing in the universe that does not change. There is nothing in this universe that is permanent and does not destroy. Everything is changing here, whether it is physical matter, an object or a physical body.
Our body is constantly changing and is becoming older moment by moment. Similarly the thoughts of our mind change, our emotions change and everything else is changing here such as money, wealth, house, car, weather, mountains, oceans, etc. Always thinking about the self, meditating and contemplating on it will help us get connected with it. Every thought, every emotion should be considered to have emanated from the self, every object and every situation should also be considered to have emanated from this self (aatma) only. Even when the object changes, we would continue to enjoy permanent happiness, as we would have attributed everything to the permanent self. This is the only way to attain long lasting happiness in this world.