After Gariga falls asleep, (while Drake's eating), he starts to have nightmares. During this time, Drake's reading a book - Cider With Rosie, by Laurie Lee (published in the States as Edge Of Day: Boyhood In The West Of England).
The plot of the book is about the '...loss of innocence into a world of understanding.'
Considering Judgement day's plot, it seems quite apropos.