I had a few problems with this book.
One: I found the title very misleading. Jimi and Isaac 5a: The Brain Injury. JIMI and Isaac. Yet Jimi was such a minor character in the overall scheme of things that, for a while, I couldn't figure out where he fit in.
Two: the back cover was extremely misleading. The back cover is written up like a quiz, 10 questions, 4 wrong. The test is taken by Jimi, Isaac's friend (Isaac is the main character) and the questions are about the accident that lands Isaac's dad in the hospital. Before I started reading, I thought maybe Jimi was Isaac's dad, and this quiz was part of his recovery, so for a while I was thrown by that.
Three: I found it extremely difficult to connect to Isaac. I think part of this was because for the first quarter or so of the book (and it's a short book, so that's a lot of pages) I was struggling to pin-point his age. I'm still not sure how old he was. Inside the front cover, a summary labels Isaac and Jimi as middle school students, who are normally between the ages of 11 and 13. Then in the early pages comes the comment that in a few months he's getting his learner's permit for driving: 16? Later we learn he's just starting high school: So...14? HOW OLD ARE YOU?! On top of that, as I read his narrative, he just felt SO young. It read like a child in elementary school, which I think also made it hard to connect. I also just found him to be a stale character in general. He didn't change, didn't grow, he just stayed the same slightly undeveloped character he started as.
Four: I just didn't get why this was a book. It had SO much potential to be a beautiful coming-of-age story about a boy coming to terms with a terrible accident. Instead, it fell short. I didn't get a sense of change in Isaac, and when I finished the book, it really didn't feel all that complete to me.
I was extremely disappointed. This story had such a chance to be such a touching story, and it just...didn't quite hit the mark for me.