Because I am the type of person that likes to be prepared for everything, it's important for me to plan ahead. It's even more crucial for a trip like this because if I forget anything, then I'm basically screwed. On longer trips, if I've forgotten something, I have the luxury of time to stop and buy a replacement. However, on short trips, time is of the essence so preparation is key.
On the positive side, the luxury of a short trip is that you don't have to pack a bag of clothes and you really only need one bag so you can breeze through security efficiently.