The return or stay in fact depends only on two things: what are your need and goal. Just as one may wants many different things during his/her life, he/she will also have many different needs and goals during different periods of his/her life.                                                                                                          The wants or desires are different from the needs. When your basic necessity/need for living (food, clothing and housing) is guaranteed, you will desire something else. But, most people will very hesitate to loose their basic living necessities in order to reach their other goals. The discussion on return or stay will never end, because it is basically this: do you dare to loose your basic living necessities for reaching other goals of uncertainty?                                                  When you have reached this stage in your life, you are now facing the world most bewildering question that can never has an answer: the goal of life. The goal of life for a bacteria, a butterfly, a rabbit, a shark, ..., a human being is in fact to return to the earth, eventually to a flame with a big bang before everything is sucked to the biggest black hole! The universe is full of black holes, the small black holes will be swallowed by the big black holes, finally a gigantic black hole will swallow everything, then another world will be created by another big bang.                                            A fire fly only has a life span only for 7 days during the spring time. But the male flies will fight to their death to find their mates and then to mate with the female flies, and then die. If they knew that they have such a short life, would they fight with each other at all?