Well... while the scientists may have proven that we use our entire brain (what i doubt VERY much), still remains the fact that we only use a very small range of all our mind possibilities. Most people dont live a brain-challenging life... in fact, most people lives a very routine life, doing the same things the same way... and while the entire brain may be used for doing this simple tasks, surely the brain is not being used at its full capacity... i would say everyday tasks uses about 1% (or less) or our total processing capacity... its like someone who has the newest computer but uses it only to play mp3... while this same computer could be used to heavy math simulations, extremly detailed graphics games, etc, and all it at the same time...
Or... we use our entire body to walk... but it doesnt mean that we are using all our body capacity when walking... we can also jog, or run... which also uses the entire body, but it uses more of our body capacity.


To the OP... i think when we are in sudden danger we are far more skillful because we are very concentrated in what were doing. When youre almost falling from your board, the only thing you want is not to fall. You dont think about anything else... so all your mind in concentrated in not falling, and thus you do what seems to be incredible feats... but they are simply the result of extreme concentration in what youre doing.
In fact we people can do things far beyond we believe. But what lack us is concentration. Our minds are like "drunk and horny monkeys, jumping from branch to branch"... we cant sustain any thought much longer than some seconds... soon, very soon other thoughts appears to compete with it, and soon our mind was taken away by other thougts... and thats why usually we are just "average" in the things we do... cause we are not concentrating enough in it.
Concentration is the key for everything. All the things called "psychic powers" are just result of great concentration, of thinking only one thought during a long time, without allowing any interference.
There is a lot more to be said in this subject... but i think is already long enough. Maybe later... :stoned: