Teaching a little kid about the world really reminds you how arbitrary everything really is. "The moon is up in the day half the time, rain is when water falls from the sky not the shower, youre going to be big and have your own kids one day" all these seem self evident to us as adults, but as a kid thats not the case and we take that for granted. Its not until later when you make sense of all these things that you understand how everything comes together. And even then there's plenty that never does. But until then, everything is just a grab bag of seemingly unrelated facts to memorize.