Then there's folks like DH and me who always seem to doing something: there are meals to prepare, other campers' set-ups to stare at while walking the campground, maybe play at the pool. A bluegrass festival (if you like that) is a great way to spend an afternoon/evening and then there are the vendors selling cool stuff:-) And people are friendlier in a cg than just about anywhere else!
If you have a car (we have a motorhome) or take your tow vehicle and check out the surrounding area. Sometimes we even read our books or watch a dvd! And even just sit around and nothing:-)