We Are All Crazy

A lady and a gentleman decide to make a child. Nine months later there is this creature that just evolved from the lady's insides. The lady and the gentleman decide to make another child. Nine months later there is another creature fighting it's way out of the lady's body. The lady and the gentleman decide it is necessary to provide shelter and food for these creatures, whom came to life because of them. All of this makes sense thus far. Nearly all animals do that. But a couple of years later, the children don't need to breast feed anymore. Yet the parents stick around. The children are called siblings. Why? Because they share the same blood. A couple of more years later, the children are fully humanly functional and can perfectly survive on their own. But the parents still get involved in their lives. They also probably live under the same roof. The siblings are involved in each others lives as well, not because of a love bond, they could hate each other for all I know but they possess that weird sibling connection. How is it that we care so much to live in groups because of blood? The world's societies are divided in the sense of having family groups. We are people who decide to stick together and be all up in each other's business because we share the same blood or parents, We are social animals who need to stay in groups to survive. But how the hell did that happen? What went about in the last non homo sapien ancestor's ,according to the evolution theory, brain? Which part of our brain grasps all these nonphysical ideals. I am so confused about the nature of life, consciousness, and reality. Which is awesome. I like confusion and craziness. Humans are phenomenal, dramatic, sensitive, and weird. WE ARE ALL COMPLICATED AND CRAZY.