Imagine this: you're sitting in a room and you look down. You see things within your reach that you can easily control and manipulate. This is what we call the 'down world.' It's the world of the present, of the here and now. But then, you look up and see things in the distance, things that require planning and effort to obtain. This is the world of the future, the world of striving and ambition.

Our brains have a unique way of managing these two worlds. They use different chemicals for each. For the 'down world,' our brains use neurotransmitters that we'll call the 'Here & Nows.' These chemicals allow us to enjoy and savor the present moment. But for the world of the future, our brains use a single molecule: dopamine. Dopamine is the driving force that pushes us to strive for things beyond our immediate reach. It motivates us to seek knowledge, love, and power.

Dopamine is like a fuel for our dreams and ambitions. It compels us to seek out explanations and meanings, and even drives our spiritual quests. But it's not all positive. Dopamine can also cause despair when we fail to achieve our goals and it can prevent us from finding lasting contentment. It instills in us a constant urge to discover and achieve more.

Interestingly, all vertebrate brains have dopamine, but humans have the most. This abundance of dopamine gives us our creativity and drive, but it can also lead to addiction or obsessive behavior. It's the reason why successful people often continue striving long after their needs are met. Dopamine makes us yearn for new horizons and relationships.

In a nutshell, dopamine is the narrator of the human behavior story. It's the reason why we tend to look upwards and forwards, always seeking more, rather than being satisfied with the present. Whether it's seeking heavenly salvation or making scientific progress, these are all manifestations of our dopamine-driven orientation. So, if you want to understand ambition, discovery, addiction, and why we can never seem to be fully satisfied, look no further than dopamine. It's the chemical that propels us to achieve great things, but at the cost of our inner peace and contentment.