This is a big problem that confused me from my childhood until now. When I was a kid around the 1980s, there was a trend consisting of looking for aliens in my country. A lot of novels were written about aliens. In that context, as an elementary student, I definitely believed that aliens existed. Especially when I walked in the dark, I hoped that I wouldn’t meet a bright and gleamy round plate-shaped big aircraft landing on the ground with some strange faced creatures coming out of it and inviting me to another planet. Their vehicle could fly faster than light, even could be turn into signal and sent to anywhere in the universe and then turned back into an aircraft. Later, more and more American movie showed us that the aliens were hostile, they just wanted to kill us and only American heroes could defeat them and save us. I began to lose my interest in aliens. As I grew up, the problems about aliens made me really wanted to know about the purpose of our existence if the aliens didn't exist. Is the fact that we are the only creatures in the universe inevitable or fortuitous? I slowly understood why a lot of famous people in history spent their whole life on finding the true meaning of life. Just like the mysterious universe, the topics of aliens are good for people, the thing we should do is not to prove that aliens exist or not, we need to pay more attention to ourselves and understand our missions. Everyone is precious and honorable.