A question that many have asked themselves, yet few have found an answer: Why are people here? What is the purpose of human life? The answer: There isn't a reason for people to be here. People don't serve a purpose. We are here, but we don't keep the world running. Without humans, the world would get along fine, probably better than it already is. I'm sure there is a deep, philosophical answer to all this, but I have yet to find it. So, for now, I will write what I have found to be the best thing I can come up with.
The simplest way that I can find to explain this is the following. First, think of the world as an old clock. Inside this clock, there are hundreds of little pieces; cogs, gears, and springs. Some people may think that humans are one of these little gears, keeping the clock functioning properly. But we are not. If we were, the world would be plunged into a nuclear holocaust if the human race were to disappear. Instead think of the world as a house. And inside this house is a machine that's sole reason for existence is to automatically drip water on the floor, and clean it up. People are this machine. If it was gone, there is no major difference in the house. The machine doesn't require any care or help from others. It works on its own, only dripping water so it can clean it up. That is how humans are. We don't directly depend on other species, and other species don't directly depend on us. If the machine were removed from the house, things would get a little bit easier: the machine wouldn't have to be walked around. And if people left the Earth, then things would get a bit easier: there would be no pollution from factories or cars, or destruction of forests, or anything of the like.
But this shouldn't be used as an excuse to never do anything. Just because there is no purpose for our existence, doesn't give us the right to sit around, saying "There is no reason for me to be on this planet, so I shouldn't have to work". To do that would be wrong. People are that little machine, dripping water and cleaning it up. That is what the machine does. As long as the machine is around, it needs to work, continuously cleaning the mess it creates. The machine needs to work, and work it shall.
An afterthought: this answer has disturbed me and it will probably disturb a few others, on account of it letting people know that they are a species that has no reason for existing, but after thinking about this for a few days in a row, I feel better about everything around me. I continue doing what I usually do, but I am much less depressed about it. I have been searching for an answer as to why I was put on this earth, and it feels great to find one, however bleak and sad it may seem. My insomnia has left, I am happier in all aspects of my life, and I have learned to let things go, knowing that I don't have an obligation to help support humanity, because humanity is pointless. In short, I am enlightened. I hope my attempt at answering such an important question will have the same effect on others it had on me.