You lie awake at 3 AM with the sheet twisted, heart pounding, room an oven 1 moment and a refrigerator the next. You flip the pillow, blame age, and promise to try harder tomorrow, while the cause sits 2 feet away dialed to 72 degrees Fahrenheit. This is not willpower. It is a thermostat that lost estrogen. Estrogen helped your body dump heat and build deep slow wave sleep. Progesterone helped you stay calm. When both fall, melatonin timing slips, core temperature rises 0.3 to 0.5 degrees Celsius, and the room that felt fine at 32 now wakes you 4 times between 11 PM and 5 AM. Hormones load the trigger. Habits pull it. This book names 45 habits and sorts them into a simple stack that moves together. Light, temperature, drinks, food, exercise timing, mind traps, tracker anxiety, schedule drift, pills, naps, sweats, and the bed you share all interact. Fixing 1 while keeping a hot room and late wine still leaves fragmented nights, and the cost shows up as 2 lost hours that cost $200 in next day performance. Inside, you'll discover: . Why scrolling in bed, TV on, and unfiltered screens shift melatonin by 45 to 90 minutes and cost 1 full sleep cycle . How dropping room to 62 to 66 degrees Fahrenheit and swapping to bamboo changes a 60 minute wake to 5 minutes . The 2 PM caffeine cutoff, the 3 hour alcohol window, and front loaded hydration that saves 2 AM trips . The earlier lighter dinner and the protein first sweet that flattens a 3 AM glucose wake . The 3 hour intense workout buffer and the morning light walk that anchors the clock for 14 days . The turn away clock, the get up rule at 20 minutes, and the 30 second 3 PM nap cap that rebuilds pressure Pick 3 cheap levers this week, cool, dark, and phone out of the bedroom, keep a 1 page log for 14 days, and bring the pattern to a clinician when needed. Sleep in midlife is not lost. It is a system you can tune, starting tonight with 1 10 minute change.