As far as I am concerned, how you understand the world is how you understand life. How you understand life is how you understand yourself. Existence is the meaning of existence. Before asking this question of "the meaning of existence", you must first realize who asked this question and to whom it is meaningful. What kind of group do you identify with, or in other words, what kind of group do you want to continue to exist because of your existence and efforts. Remember, how you understand the world determines how you understand life, and how you understand life determines what you will do and what you think is valuable.