I actually kinda felt like that with our June, 2007 trip. I started planning the trip in August, 2006. All year long, I bought the little things I knew we needed to take with us. I bought new t-shirts and shorts during the Winter because you can get them sooo much cheaper that way.
I made all of our dining reservations at the 180 mark. I read all information I could find on refurbs. etc.
About two weeks before our departure date, I went to the store and bought the road trip snacks. I bought our fix-a-flat.....just in case.
Then, about a week to ten days before our trip, I just didn't know what to do with myself. Everything was done except for the packing. It was too easy! I know that I should have been happy that everything was done but I was just a little let down that no planning was left. Of course, the night before the trip, I was all pumped up again.
Our May/June, 2008 trip was booked in mid-August, 2007. I can make our dining reservations on December 2nd. I've already bought a few things for the next trip. I'm doing it again!