How many worlds?

How many worlds are there? The Answer is there are as many number of worlds as there are as many number of humans. My view is each human being has his own world. He is the Hero of that world. He forgets or lives in the concept that others do not have their own world. Your world is what you see through your window of understanding. How many times we realized that there exists worlds of other people? Individuals, communities, states, countries or nations think and live in individual concepts forgetting there exists other concepts which are as legitimate and logical as their own.