Over and over again, Ursula Todd lives through two world wars. She’s never in as much control of her death and rebirth as characters in The Edge of Tomorrow, for example, but she does learn from her multiple lives. It’s somewhere between deja vu and being able to completely accurately predict the future (because you’ve already been there).
I have to admit to being disappointed with this book, but I don’t think that’s the fault of the book. I just wanted it to be something other than what it actually was. I wanted it more like The Edge of Tomorrow (though, come to that, Emily Blunt would make a great Ursula Todd).