4.5 stars 
 Madeline lives with SCID. She doesn't get to interact with the world. And she's mostly fine with that. She's got her own little world that works for her with her mom, her nurse Carla, her online classes, and her books. But when new neighbors move in across the street, Madeline finds herself watching them and longing for a bigger world. 
 The tone of this book is quirky and cute, but it works. It keeps things from being bogged down. And despite everything, Madeline is not a cynic. She has hope. And she is making discoveries, and learning about herself. We get to go on that journey with her. It works. Twists in this book that I thought would make me eyeroll were handled with charm and honesty. 
 The characters in this book are handled so well. They are revealed through their actions deftly. Madeline describes them a bit, but they stand on their own. And the narrative is so forgiving of these people's complexities. With one exception, Yoon does not seem to want us thinking in terms of good and bad. It would be so easy to have Madeline resentful of the life she's had to lead, and thus resentful of the people in that life. But she's a bigger person than that. And even when she is frustrated by limitations, she is understanding of the other's perspective, allowing us to be too. 
 This is a quick read that will fly by even faster because it's so engaging. I can't wait to be able to start putting this book into reader's hands. 
 "You're not living if you're not regretting."