Granted, I think with the Smithsonian this phenomenon tends to be
exaggerated. After you started at Air and Space in the morning, hit
the National Gallery sculpture garden/ice skating rink, and then run
over to Natural History, your average adult is foot-sore and more
tired than the kids, who are refreshed after sitting down for 15
minutes and eating lunch, or who have been carried by obliging
adults. Some adults just aren't into museums and extracurricular
learning, and whether we like it or not, they are the ones who take
the children from one place to another.