Have you heard the "Four Burners" theory that's in 
this David Sedaris story?  I heard it referenced in an awesome radio podcast called 99% Invisible a  few weeks back and it's kinda stuck with me. Not sure I necessarily  believe it, but it speaks to the difficulty of finding that balance in  your life.
 
 
"One burner represents your family, one is your  friends, the third is your health, and the fourth is your work.” The  gist, she said, was that in order to be successful you have to cut off  one of your burners. And in order to be really successful you have to  cut off two."
 
Honestly don't know which burner I'll turn off over the next decade. The  alternative, of course, is to have a couple of 'em on low and find a  way to be content with that.