The Ten-Three-Two-One Rule

Most sleep problems are not insomnia in the medical sense, they are evening choices that sabotage what would otherwise be a perfectly normal night. The ten-three-two-one framework is a simple rule of thumb that addresses the four most common offenders.

Ten hours before bed: stop caffeine. Its half-life is around five to six hours, which means an afternoon coffee at three in the afternoon still has measurable effects at eleven. Three hours before bed: stop large meals. Active digestion raises core body temperature, the opposite of what you want for sleep onset. Two hours before bed: stop work. Cortisol triggered by problem-solving lingers for far longer than the task itself.

One hour before bed: stop screens. Bright light at any wavelength suppresses melatonin, and the dopamine-driven content keeps your brain engaged when it should be powering down. Read a book. Take a warm shower. Talk to your partner. The night you wanted starts an hour earlier than you think.