The Richest Man in Babylon

I read this book in a few days with time permitted. It got kind of puzzling towards the end as the narration confuses me. The author wrote this book like it was some kind of Bible. I took notes but it was mostly common sense item. The different rotating characters also confuses me. Who is who and do they have any connection with one another? Why is this book such a classic? Why didn't someone make a movie out of this if it was such a best seller? Where is the value in the book? This book can probably be summarized and learn from through spark notes or the likes - just my opinion. Or must I read it again to fully understand the concepts?