Self will, limits of being human

What are our limits as human beings. Ive allways wondered this. Its kind of hard to put words to how i feel. but ill try. There are some things i dont understand about how we live.We have the choice to do whatever we want. And sometimes we desire to accomplish great things and fail.Look at the society we have build . We no longer look at ourselves as the center of the universe but understand that we are just a little small spec in the big picture.but im off topic. when we are tired we sleep when we are hungry we eat. But what happens when we deny ourselves these things. Is there somthing to be learned from it. Learning to controll ones self. Why is it so hard to control ourselves. I dont know may be we were born with the ability but lost it growing. Ive heard of an experiment done on infants once to figure out if the child had no outside influence what languge would he speak. so they gave these children only the essential things of life food and a living enviroment. It was only a short manner of time before these children died. They had no reason to live and even in their confortable environment able to give up there own life with just will. The world we live in we have created down to prosperity poverty and government. If we created the value we put behind gold. Why when we die we feel or have read the streets will be filled with it.God may have made the material but it was man who made the value put behind it. Is heaven also man made. Remember the tower of babylon story were people all united as one to build a tower big enough to reach god. People united together for one cause why was the tower struck down? they were getting no where we now understand the sky doesnt seperate us from the heavens. I think the people who written that part of the book would have written it differently if they understood this.as i meditate i try to concentrate on one thing but my mind wonders just in that one sitting my mind pulls out so many unnessesary thought just for the reason for me sitting their and trying to think just one thing. But why  cant i just choose to think one thing. Mabey its a habit embeded into my cerebral cortex just to think that way. And if thats the case how long will it take me as an individual to create habits that i design. The only person who can figure out the reason of life is the individual.Somtimes its alot to think about and too much to understand. Why fear what we dont understand. Death , sin and awful coincidence. For that we put easy escape roots that lessen that fear like The thought a perfect world (heaven) a perfect being (god) and a perfect evil.(satin)So when we die we can reach that perfect world where there is no use of thinking. because to live in that perfect world everyone will have to live perfectly to make it perfect. so in that case what is god when we die. And for awful fate we create the ultimate evil. To strike fear into those who do evil. But also the give excuse to our evil doing instead of taking full responsibility for our actions and all the bad things that happen to people for no reason at all. Why are we so afraid of death. We are afraid to end but its life we all die. And choose not to live to better the world we live in but only to better ourselves.