Firstly, I must say I find it bizarre that the above, very dismissive, review was posted by someone who failed even to finish the book.
That being said, here's my tuppenceworth... Many great works of literature are based on journeys of exile and return, from the greatest poem of all, Homer's 'Odyssey' (which I had the pleasure of studying in Greek this semester), to The Hobbit. These stories make us ask deeper questions about life, its purpose and direction. 'There is One of Everything in the World' is an attempt to introduce the genre of 'journey literature' to a younger generation, who are very much in need of literature that makes them ask the 'big questions'. It achieves this goal in a way that is original, quirky, funny and wise. Not many books for young people will hint at sources as diverse as medieval Irish 'immram' tales (the 'Navigatio Sancti Brendani'), the Book of Exodus ('a stranger in a strange land'), and Arab reflections on sea-travel (Amru bin al-As). These references are light touches, however, and the overall tone is humorous and fun, with some vivid characterisation (the character of Glic is particularly well-drawn). Scenes to do with drinking and eating are particularly well-described, which add to the atmosphere of fellowship (think of Tolkien's descriptions of the hobbits' feasts).
As I read this, I kept thinking that I would have really loved this book as a young teenager, when I was something of a dreamer. This book would suit any young person who likes to read good, thought-provoking stories.