I don't know what it is. Maybe it's the chaos factor of Pennsic. You know that something is going to happen, but you don't know what, when, who will be involved, or whether it's going to be totally awesome or totally apocalyptic. I mean, I met Carl at Pennsic 31, and we are (thankfully) still feeling the shock waves of that cataclysm. :-) The control freak in me quakes before the inevitable mayhem machine that is my two weeks at Pennsic.
I forget until I actually set foot on site how priceless that mayhem actually is, and how much I value all of those moments that don't seem to take place anywhere else.
Like listening to the rain on the tent while curled up under the covers with Carl and Wendy, or visiting with Mollie late at night like little girls at a sleepover (who talk about explicit sex acts), or meeting Luna Lovegood on speed, or doing drunken diaper delivery with Wrenne, Frannie and Bree, or waking up and having cups of tea under the canopy of trees with whoever is conscious...
It's why so many people go back again and again, I suppose. Because we miss those people and that feeling that we belong somewhere special. Even if that place only exists once a year.
Of course, if I could just move all of my friends into my town, it would save me the anxiety attack every summer...and the two-day packing extravaganza...and we would get to smell each other under normal, non-camping circumstances, which would be novel*. I'll be sure to put that at the top of the list when I send out the brochure.
*except for the smelling of Wrenne. she always smells luscious. always.