I do pack a set of clothes for my dd6- usually just a light sundress and underwear. It takes up almost no space and we have used it before because of water rides. I am definitely a "Oh, it will dry.." kind of mom. However, the River Rapids drenched us (even underwear) and we were glad to have that change of clothes. I like the piece of mind of knowing I am prepared for anything (and when it is just a thin dress..it isn't a big deal).