Registered for the State Time Trial Championships

One must question my mental capacity right about now. I just registered for the Idaho State Time Trial Championships (there I am). That by itself isn't enough to qualify me for the loony bin, but the fact that this is a 40km time trial . . . now that's nuts: 25 miles of all-out effort. I've never even spent that much time on my TT bike. My longest ride on it was my very first - 14.5 miles. And of course I was just getting used to it so I put no real effort into that. I have no idea how hard I should go out on this thing in order to have enough left to finish it. But it should be . . . fun? :)