So Yesterday is a novel by Scott Westerfeld published in 2004. It has won a Victorian Premier's Award and is also an ALA Best Book for Young Adults. We are all around you. You don't think about us much, because we are invisible. Well, not exactly invisible. A lot of us have hair dyed in four colours, or wear five-inch platform sneakers, or carry enough metal in our skin that it's a hassle getting on an airplane. Quite visible, actually, come to think of it. But we don't wear signs saying what we are. After all, if you knew what we were up to, we couldn't work our magic. We have to observe carefully, and push and prompt you in ways you don't notice. Like good teachers, we let you think you've discovered the truth on your own. And you need us. Someone has to guide you, to mould you, to make sure that today turns into yesterday on schedule. Because frankly, without us to monitor the situation, who knows what would get crammed down your throats? It's not like you can just start making your own decisions, after all.