"The past is a curious thing. It's with you all the time. I suppose an hour never passes without your thinking of things that happened ten or twenty years ago, and yet most of the time it's got no reality, it's just a set of facts that you've learned, like a lot of stuff in a history book. Then some chance sight or sound or smell, especially smell, sets you going, and the past doesn't merely come back to you, you're actually in the past."