The fine art of balance.

This is something that I used to get caught up in many times. Balancing the real world with play world, and within that play world, balancing your time and player time, balancing each character's 'shining' time with normal time with 'not-so-shiny' time (as in when they are the star of the show, a player in the show, or not that big a part at the moment).
Being a GM is very much about balance.
Putting it into real world examples: a few days ago I was juggling spending time with my almost 5 month old son, eating, and trying to get some things done with Demon-World (I'm gonna abbreviate that to just DW from now on heh). Needless to say, I spent most of the time with the kiddo as he had just woke from a nap and was needing some attention and play. I was able to get about 25% of what I set out to do that day with DW complete, aye I was a wee bit ticked that I didn't get more done, but I was happy to have some things I moved forward. And I worked just a wee bit harder the next day and made (mostly) up for it. Ah speaking of... need to put up the stuff that Trey helped me out with... I was rearranging it so it looked a bit more easy for me to read.
There is also something about balance when ye are planning on being both a GM and a player (I'm planning on for DW to become a multiple GM endeavor around Mission 30-ish and making myself a character to play in it when other GMs are running a session.) As a GM, especially the Head GM, ye need to balance what ye know of your world and what your character would know and would do. I've honestly seen more GMs slip up on this rule then just about any other... It's not fun, it leads to parties going "Ok, just follow the GM-Pet, they know where to go...".
Good planning and great balance can lead to a very happy RolePlayer and a very happy game.