People claim that humans are here on earth for a variety of reasons. There are all kinds of theories as to our origins - from Adam and Eve, to an Anunnaki alien experiments, from extra-terrestrial star children, to the cycle of death and rebirth, from the idea that all life is an illusion, to the idea that the true reality is oneness.
All of these are great stories, and they are all true in this sense: They are completely made up, and they completely miss one key point. Sex.
In my mind, humans exist unquestionably for one purpose; to have sex. Sex has made us who we are today. Without sex, there is no humanity, there are no myths, no religion, no stories, no us.
Sex is the key to life.
Our sexuality is symbolic. If you come join me on the savannas of Africa for a moment, and we imagine overlooking the edge of a cliff, in the distance, in the valley below, a lone human figure walks in the heat of the noon sun. Because of the symbolic shapes on this human's body -- in particular rounded ass and breasts -- or a flat chest and a dangling cock, we can easily identify a female form from male form even though we are miles away.
Sex is symbolic, and it hews a symbolic body - one meant to release sexual energy. Looking at a naked body we are meant to feel intense things. A dangling penis is for sexual attraction, as is the erection. When a man is aroused, we know it. I personally spent most of my high school years relentlessly harassed by my penis, and the untimely tent in my pants. (Wait, is there a song there?) A good erection is also symbolic of good cardio-vascular health.
Our beautiful body shapes are meant to trigger strong, sexual responses. We are made to attract for sex, and the one thing we can surely count on in life is that at some point we will have sex - with ourselves - or someone else.
I'm suggesting that perhaps the main purpose of the human being is to have sex. All of our stories, our myths, our religions, our fears, all of our tensions and worries, and our endless relationship dramas, our heavens and our hells, our relentless attempt to control our impulses, are nothing more than a distraction -- a ways to keep our conscious minds from focusing on the simple, understated purpose of life -- having delicious, intimate, loving, wonderful, vulnerable sex.
Looking at life that way, it truly is a beautiful world.