what I learned in college...
life. life for all of us consists of thought. thought in as much as all forms of perception are thought. We organize thought into compartmentalized scenarios. constructs. compilations of perception. this is how we organzie our existence. through these groups of expectations. expectations of cause and effect. also expectations of others and the expectations that others put upon us. If I drop something it will fall. People should be nice to each other. That guy is nerd because he wears glasses etc. etc. How these constructs come to exist, this brings us to the old addage of nature vs. nurture and its modern synthesis. All you are is the end result of your physical being(genetic,evolutionary, molecular, etc.) combined with how this physical being has reacted to the combination of every single occurance that has happened to it, regardless of how miniscule. But don't forget. Don't forget your power of choice. You can reject a construct. re-write the script. synthesize new constructs independent of personal experience. novel thought. creativity. But isn't this pre-ordained? how can anything new, anything spontaneous exist in the face of causality? The same way each person is unique regardless of the physical occurances that brought them into existance. Look into the sky and realize that when your life began the possible outcomes for the present were more numerous than all the stars, seen and unseen, but instead of those myriad permutations, it is you who stand and wonder.