Saying you can relate to what the author describes means that you can fill in the iceberg below the surface. I'm not sure I can say that for those without kids developing an appreciation for the magnitude of this iceberg is possible without having a child. I'm still learning how to dad and part of that is sharing the experience of the phase transition from childless to parent with those who have yet to or choose not to pass through the transition. With enough time and thought (which is hard to come by when you have a kid), maybe I'll get there.