Happiness comes from within - the same can be heard in the mouths of successful people in all religions and in their respective positions. But why?
Suppose, your salary has increased today. Generally you are supposed to be happy. But you are not happy. It seems from yesterday that you have a big disease in your body. Or you have to pay tax on the new salary increase. As a result, the money has to be paid as tax near the salary which has increased and at the same time there is trouble. So even if the salary increases, you are not getting much happiness. But your family is happy to raise your salary. Friends are happy too. They want treats. Even if you don't get happiness, others get it, what is the reason?
There are about 600 crore people in this world. This 600 crore world sees with their own eyes. Everyone has different filters in their eyes. One sees the same event differently with their own filters. Everyone makes their own world like their own. Much like the solar system. The sun is the center of the solar system and everyone is the center of their own world. And the rest of the people we have relationships with are all around us. Many things happen every day in our own world. Some of it is personal. For example: getting a new job or getting married. Which again happens in the middle of everyone in their own world. Such as: sibling or friend's marriage or job. Which also touches the other world. Such as: various disasters