Your positive attitude. Don't worry about it. Anything you forget can be dealt with for a night or two. Just relax, make note about where things are located, and go enjoy it.
Over the years, I've spent 4-day trips without one of the following:
Fridge (had a friend bring a bag of ice out, keep a soft-sided cooler in the cupboard)
Fresh water (used the campground facilities)
Electrical power (used LED lanterns and the campground facilities)
Propane (cooked on the fire)
Sure having everything is great, but it shouldn't ruin your trip just because you couldn't figure out how to turn on the water heater for two days.