Ohhh I loved this book. I read it in a day while we were upstate and have been thinking about it - in a good way - ever since. It's The Midnight Library by Matt Haig and, as usual, I heard about it from Bad On Paper podcast / Grace Atwood at The Stripe.
Little trigger warning up top as the entire book deals with suicide; the main character attempts suicide at the beginning and the plot grows from there. So if that will really upset you, I would skip this one.
The number one thing I loved about this book is the way it frames regret. I've talked a bit before about Brené Brown's podcast that mentioned regrets only being worthwhile if you learn from them, which is an idea that I like. But this book represents the idea that you could go back and look at your regrets from another angle, one in which the regret in question set into motion a sequence of (seemingly, to you) unrelated events that affect your life in ways you can't fathom. I don't want to ruin the book but it is a bit like the Gwyneth Paltrow movie Sliding Doors in that way. A fantastic movie in its own right.
Anyway, the way it described regret, an afterlife, and fate were all beautiful and thought-provoking. I also love books based on British characters, always have. There are elements that are funny, some that are relatable, and the overall feeling I got from reading it was warmth. Highly recommend if you want something to curl up with for an entire weekend.