One of the inherent troubles with a retrospective novel is that readers know the narrator is telling the story from a point in the future. The events have happened, and the narrator survived them (since they're telling the story). So there's very little fear about the narrator surviving. To combat this, you'll often see a narrator who's at a point where they're about to die, and they're telling their story before they're gone. Again, this has tension issues because you know they made it to this point, and if they're about to die, why does any of it matter? Writing retrospective that works well takes skill.
And John Marsden has that skill.
Tomorrow, When the War Began by John Marsden
This was a great book and one I really enjoyed. Australian teens come back from a camping trip to find their country's been invaded, and they decide to live off the land and fight back guerrilla style and save their families. There are seven (I think) in the series, and I'm going to have to order them soon.