There is a hierarchy to existence, and humans are the peak of that hierarchy. All people--including you--are the fullest expression of existence, the very most that can be.
All things that exist, including man, have specific natures. The nature of most things is simply physical. By physical I mean that aspect of reality we can see, hear, touch, taste and perceive in some way. All that is physical can be explained entirely in the physical terms of position, motion, and acceleration. The hardness of rocks, the movement of air, or orbit of planets, the pull of the tides, and the burning of the stars can all be explained and described in those terms.
However, some things cannot be explained entirely in those terms, such as a salmon swimming against the current to reach its breeding ground. There is another term used to describe those things: life. These things are not only physical, they are also living. Life is not physical, for it cannot be seen, touched, tasted, or perceived in any way (note: I know this view is unpopular and obscure, and will get me branded as unscientific). We know an organism is living by observing the behaviour of its physical aspect, not be perceiving that aspect of its nature that is its life.
The nature of life itself has several qualities, but I think the important one for you is understand is purpose. To quote The Nature of Life:
"For merely physical events, there is no connection between the cause of the events and the consequences of them, except the physical events themselves. For living behavior, however, both the cause of the behavior (or what makes it possible), and the consequence of the behavior (what it produces) is the same thing, the life of the organism. There is no other reason for living behavior than the sustaining of the life which makes it possible. There is no reason for any physical behavior except the laws of physics, but the life process has an end, a "purpose," which is the life process itself, and without that end, there would be no life process."
All living things have purpose, which means the universe has purpose (because we are part of the universe). Again, from The Nature of Life:
"as astounding as the physical universe in all its grandeur is, without life it is a pointless show in an empty theater that would never be seen or matter. But the universe does have a point, because there is life in it, and it is astounding, because we are in it to be astounded by it."
All living things are sentient in some way--it is that sentience that allows an organism to respond to its environment in the way we call living. Some organisms are more than just sentient, they are conscious. A conscious organism does not only react, it can learn, and because it can learn it can enjoy. I don't mean "enjoy" in the sense "I enjoy this TV show", but in the sense of an animal living successfully in accordance to the requirements of its life.
Ultimately, to enjoy life a person must live in accordance with their nature as a human being, just like how the animals to survive and thrive must live in accordance with their natures. The animals have "instinct", they have a "built-in program" that gives them the rules to live by. Instinct "tells" them how to live in accordance with their natures.
Humans are different from the other animals, they do not have instinct. Humans are volitional--their nature requires they choose how to live. Volition is the final level of the hierarchy. Humans do not have instinct, when we are born we don't have built in rules telling us how to live. People can be miserable because the can choose (knowingly or unknowingly) to live contrary to human nature. Sometimes living contrary to your nature can be immediately fatal, like how poison is contrary to the nature of your physiology. And other times the effects are not immediately fatal, but are are damaging in other ways, such as choosing to let others choose for you (which is like having others live your life), or not learning (knowledge is a requirement for making choices), or not being productive (to live you must sustain yourself, which requires productive effort, which to be successful requires correct choices, and to choose correctly you must gain knowledge through learning).
In the hierarchy of existence you, as a human being, are the pinnacle of that hierarchy. You are the fullest expression of existence.
Most of existence is only physical. A much smaller part of existence is physical and living. An even smaller part of existence is physical, living, and conscious. And the rarest of all existents, which is you, is physical, living, conscious, and volitional--the very fullest expression of all that can be, the very purpose of the universe.
