I dont think anyone realy grasps the gravity and importance of family until you have your own. I know I didn't. But in hind sight, I cant think of anything that my life couldn't do with out, accept my upcoming baby boy. smile.gif It WILL realign your perceptions.
In close second, I would have to go with this:
http://www.summitpost.org/images/149399.thumb.jpg Clicky. To the doubters, I say try it. No singular activity challeneged me more, nor effected more emotionaly then completing that. I've never felt like I did, standing on top of that rock. Of course, there are more to come.