Ok, to bring this back on a serious note here is my theory.
We humans have a body, Scientists proved, that is meant to live forever. The degredation of our body over the years cannot be accounted for even in the best earth and life conditions. It is true certain unnatural things made by us humans have proven to degrade our body over long periods of time. Anyways, our bodies were designed to live forever, dont beleive me do some research.
This theory being proven by many in the scientific community, brings us to the 10% theory on the use of our brain. What i think scientists mean when saying that is most likely contributed to motor skills. I beleive they think we only use 10% of our brain for motor functions, some go over that with great abilities such as fastest sprinter, genius minds and more.
Another thought of mine is tied to the fact we are meant to live much longer then we currently are. It is proven the farther you go back in history, the lifespan (under normal and natural surroundings) increased greatly. Living over 100yrs was not something special 100 yrs ago or 200 yrs ago in some places, it was a normal occurrence. Only recently in the past 20 or 30 yrs has lifespan greatly decreased. Since our knowledge has increased so has our life expactancy decreased.
So living longer, our bodies not meant to die, brings around the reason why we only use 10% of our brain. We simply cannot live long enough to reach the 100% potential. All we can do is hope we can multiply our 10% through books and passing along teachings to future generations in hopes we can achieve greatness through intelligence.
Basically we use 10% of our brain only because we dont have enough lifetime to actually fill it any further. Imagine if Einstein lived 50 more years? He might of maxed out his brain already, if he lived 20 more years or 50 more years he might have been considered even more genius and our world today would be drastically different.
If you tie religion into this, you can have a great many debates on a variety of possiblities. Fact is no one really knows how much brain we actually use apart from brain functions related to motor skills. We can only assume 5% is motor and another 5% must be thought and perception and other mind boggling things. We can never truely know.
I for one beleive we as humans should be able to live longer and if we did the knowledge and experience achieved would be so great it cld only be compared to Godly. Which brings us to another subject. you know how "the man" keeps you down so to speak. Well maybe this is God's way of keeping "man down" by lowering our life expactancy or knowing we cld do that on our on, in hopes we never achieve his greatness in knowledge. He may be just some alien who scientifically made us then got scared of us and made us suffer with life expectancy in hopes our knwledge can never reach his. Who knows.