A book is a dream that you hold in your hand.
What's rather lovely here is Gaiman's insistence that books aren't containers of information—they're *experiences* that only exist in the act of reading. The dream metaphor matters because dreams aren't logical or linear; they work through image and emotion and half-remembered logic, which is precisely how novels move us. A friend of mine once told me she'd reread the same beloved book three times and each time lived a slightly different dream, depending on what she was carrying in her own life that year—the pages stayed identical, but the experience transformed.