A Night of Sleep, Mapped: Deep Sleep, REM, and What Protects Each

A 4:3 diagram of sleep architecture across a typical night — deep sleep front-loaded into the first hours, REM lengthening toward morning — with the three habits that protect each stage. Useful for CBT-I psychoeducation, sleep-habit conversations, and explaining why a consistent wake time matters more than an early bedtime. Prints as a one-page handout.