What was the last book you read that you really didn't think you would like, but did? (please read details)

Not an assignment, not a textbook, but something you read because you sort-of felt you had to? It might have been a gift from a friend who really wants to discuss it, or a biography written by a friend and you said you’d read it so now you have to… For example, I am in the middle of a biography of a race-car driver. On the face of it, I can’t imagine anything I am less interested in, but my friend wrote this book, and in a silly fit of solidarity and support I promised I’d read it. And I’m really enjoying it. And I am amazed. What book has surprised you like this recently?