It's even funnier when you realize they have to strategize to be able to carry it on their heads. If those things measure roughly 18 inches by 24 inches they would hold over 200 lbs of water. That means the nogs have to avoid filling them all the way to carry them on their heads. So not only do they have to not understand the concept of the wheel despite seeing other people doing it, but they also have to be unable to ask themselves why a container would be designed to be so much larger than is possible to carry when full.