One of the many reasons human cultures have long associated sleep with death is that they each demonstrate the continuity of the world in our absence.

Sleep is not a dead space, but a doorway to a different kind of consciousness—one that is reflective and restorative, full of tangential thought and unexpected insights. In winter, we are invited into a particular mode of sleep: not a regimented eight hours, but a slow, ambulatory process in which waking thoughts merge with dreams, and space is

There is nothing more human than the experience of lying in the dark, wondering: What if I don't wake up? In that way, sleep becomes existential cross-training: dread faced nightly, and nightly overcome.