You've done everything right. Dark room. No phone. Magnesium gummies. The app that plays rain sounds. And still you lie there at 11pm, wired, waiting to switch off.
Here's the thing most sleep advice misses: your nervous system doesn't have a manual off-switch. It runs on signals, not willpower. Through the evening it's supposed to shift from fight-or-flight (sympathetic) into rest-and-digest (parasympathetic). On a good night, that handover happens quietly in the background. On a bad night, nothing triggers it — so your body just keeps idling in gear.
The signal your body is waiting for
One of the most reliable cues for sleep onset is a drop in core body temperature. As your core cools in the evening, the brain reads it as "time to power down." A hot bath works precisely because of what happens after you get out: your warmed-up core temperature falls fast, and that rapid drop is the exact signal your brain uses to begin sleep.
It's thermoregulation, not magic — and it's the mechanism behind the Tune ritual. Twenty minutes, hot water, the same time every night. You're not forcing sleep. You're giving your body the one cue it's been missing.