This book managed to surprise me in a lot of ways. In a good way. You have four people, four plots, for very different perspectives and no idea how or why they're connected.Though there are four different plots, I didn't get confused about who was doing what and with whom and why. You know how it happens sometimes, that you get more than one plot and it's not very clear when the story changes and when the perspective shifts and you are left wondering "What the hell am I reading?". I didn't feel that with Differential Equations. And I didn't feel that the stories where lacking some details, or that they were thin. Even though you get four stories, they are so well written and so full of details, I felt like I was reading four books at the same time.There are a lot of surprises. Each and every time I managed to think of a way these four people were connected, the following chapter would always prove me wrong. I think that's the one thing I loved most about this book, the fact that I wasn't able to foresee anything. There might have been little things that made sense to happen in a certain way, but the important things were a mystery to me until the very end of the book.There were several scenes that made me very sad in this book. I guess they were a sort of lesson for the main characters, but I still felt incredibly sad for them. That's another amazing thing about this book, the fact that I felt so connected with the characters. And it was one of those books where you can't stop reading.It was an amazing read and I think you should give it a try.