You'll be sick or feeling troubled or deeply in love or quietly uncertain or even content for the first time in your life. It won't matter. Out of the blue, beyond any cause you can trace, you'll suddenly realize things are not how you perceived them to be at all. For some reason, you will no longer be the person you believed you once were. You'll detect slow and subtle shifts going on all around you, more importantly shifts in you. Worse, you'll realize it's always been shifting, like a shimmer of sorts, a vast shimmer, only dark like a room. But you won't understand why or how.
Mark Z. Danielewski
House of Leaves