What's with "Guess How Much I Love You" storybook? Why are parents crazy about it?

My cousin used to read this to her 6-year old son. She mentioned that her little boy imagines himself as the little nutbrown hare and his dad as the big nutbrown hare. What made it so special was the thought that her son adapted how the little nutbrown hare declares his love to his big guy. Based on the chitchats of my cousin, there were even times when she will caught his boys saying i love yous to each other until the other one gets tired. It became a father and son bonding. I also read the book, and will surely purchase it for my future kid. Major add on: it only costs Php 295 in National Bookstore.

It's such a timeless story depicting a parent's love. I guess we can all relate to how we are unable to express how much we love our children and just have this big big feeling in our hearts. To the moon and back is a good visualization.