There is nothing better than building a sand castle with your 2 year old to make you forcefully appreciate the transience and imperfection of things. You want to make it a certain way, but he has other ideas. So you let it go. You compromise and you build it his way, but then he destroys it and has a great time doing it. So you learn to laugh it off too. There is so much I can learn from my son, but as always, I remain a slow and reluctant learner.