Sleep
The architecture of the night: cycles, stages, REM. The physiological ground everything else is built on.
Sleep is not one uniform state: it is a succession of roughly 90-minute cycles, each moving through distinct stages — falling asleep, light sleep, deep sleep, then REM sleep.
Why it is central here
Almost everything explored on this map runs through sleep: dreams and their recall, sleep paralysis, the states of consciousness at the edge of falling asleep (hypnagogia). Knowing your own cycles means knowing when and how to intervene.
Landmarks
- Deep sleep dominates early in the night; REM dominates late — which is why end-of-night techniques work best for lucid dreaming.
- Sleep deprivation massively degrades memory, mood and health, and this is thoroughly documented.
- Sleep hygiene (light, regular hours, temperature) remains the most powerful lever, before any gadget.