Worldwide book requirement

If I had the ability to assign one book that the whole world had to read I would assign "One Fish, Two Fish, Red Fish, Blue Fish" by Dr. Seuss. I choose this book over all the books in the world because I find that it tells people about diversity, and that diversity is not a bad thing. There is an old saying "There are plenty of fish in the sea." And it always comes to my mind when I read this book.  In the saying "fish in the sea" really means "people in the world". The many different types of fish named in Dr. Seuss's book are like the many different types of people in the world. I also appreciate that this book appeals to people of all ages.