100 years from now..

100 years from now, almost all of the people we see in the world today won't exist anymore. It will be a whole new generation of people. A whole new generation of love, hate, generosity, greed, peace, war, happiness, misery, health, disease. I wonder whether people think about their legacy and what they are really leaving behind in this world. Why do we have so many people who are arrogant- considering our lives are so short?