Keeping life interesting

What is it that we strive for as human beings?  People enjoy accomplishing things and being able to say, yeah I did that...  but what lies behind that basic human instinct to push ourselves?  Is it our competitive nature, the yearning for new adventures, or is it something more deeper then that?

recently I've picked up rock climbing at an indoor gym with my son, we go, do some climbs and I often think i'm pushing my son too much to climb harder grades then he believes he is capable of accomplishing.  sometimes it's a struggle to get him to try a harder climb, i think his lack of interest in trying it is the sense of failure.  we sometimes don't do things because we don't want to fail at it.  Much like when you are young you don't ask out that girl because you don't think you have a chance, or that you don't want to get rejected.  I believe the same thing happens in every other aspect of life, people don't try new or harder things because of the fear of failure.

the funny thing is even when we expect the worse and do fail there is always a sense of success when we try at those things, for example while climbing on Sunday we've climbed a bunch of 5.9 routes successfully and failed at some 5.10 routes that are just out of our technical know how and ability right now.  But there is a 5.8 climb at the gym we go to that appears daunting, two good overhanging ledges.  This route isn't technically difficult, however it is mentally and physically demanding to be able to get over these two overhangs.  I gave it a go myself and almost got above the second overhang but yet failed.  After my go at it, I convinced my son to give it a go and he did better then he expected and even had a look of satisfaction on his face that he accomplished something.  That feeling of accomplishment is great, it will lead him to believe that he CAN do it and give it another try the next time that we go.