The one thing everyone seems to forget when they go camping is moist wipes. Seriously. Swamp ass is miserable. That and bug spray are the first things I pack before everything else. Clean socks, clean underwear, clean nuts, butts, and pits. The necessities of life.
I like to bring a secret stash of beer nobody else knows about. Nothing is worse than running out of beer when you are camping in the middle of nowhere.