Many things in our universe only co-exist. For example, when you pull on a rope, it gets longer and thinner. Tension and compression only co-exist. In other words, you can't have tension where compression does not occur.
Another example is convex and concave. You can't have one without the other.
A third example is expansion and contraction. When a balloon expands, it causes the air outside of it to contract. Expansion and contraction only co-exist.
The yin-yang symbol is one way of symbolising the world as a place where opposites always and only co-exist.
We live in an expanding universe.
The process by which the universe expands and becomes less ordered and more random is called entropy.
If the world is a play on opposites, what is the contracting and order creating force that counterbalances the expanding entropic universe? What is playing the role of the anti-entropy? Since the universe is everywhere, we should be able to see it everywhere! Where is it?
Look in the mirror - It's You!
The physical is inherently entropic, giving off energy in ever more disorderly ways. The metaphysical is antientropic, methodically marshalling energy. Life is antientropic. - R. Buckminster Fuller
In other words, it is lifeforms in general and the mind of man in particular that are the anti-entropic force in the universe. As humans we organize things both mental and physical, thereby contracting energy and creating order to counter-balance the expanding entropy of the universe. This is the supremely important purpose of intelligence and the reason why our minds exist.
Whenever we think, or act to create order in the physical world based upon whatever we think, we are performing the anti-entropic function without which the universe would not be in balance. That is our purpose in life and why we exist - to think and thereby to create mental and physical order - because that is how we carry out our all important function and essential contribution to the universe.
Therefore we are pretty damn important, we humans.