I just had my first Longhorn half-ironman nightmare this morning. I had a dream where I was out riding my bike around my hometown for a last minute workout and completely forgot to check in for the race. The event has the bike check-in/packet pick-up the day before the race, and if you don't pick those up the day before then you don't get to race. You can imagine why missing this would be a bad thing.
I'm sure I'm going to have more of these in the upcoming weeks.